| 92% |
With sodium tetrahydridoborate In tetrahydrofuran for 0.6h; Heating; ultrasound irradiation; |
|
| 92% |
With sodium tetrahydridoborate; diammonium oxalate In acetonitrile for 0.166667h; Reflux; |
|
| 91% |
With sodium tetrahydridoborate; sodium hydrogen sulphate In acetonitrile at 20℃; for 0.0833333h; |
|
| 91% |
With sodium tetrahydridoborate; pyrographite In tetrahydrofuran; lithium hydroxide monohydrate at 20℃; for 0.0166667h; |
|
| 91% |
With sodium tetrahydridoborate; lithium hydroxide monohydrate; titanium(IV) dioxide In acetonitrile at 20℃; for 0.333333h; regioselective reaction; |
|
| 90% |
With sodium tetrahydridoborate; Dowex1-x8 In tetrahydrofuran for 0.7h; Heating; |
|
| 90% |
With sodium tetrahydridoborate In lithium hydroxide monohydrate for 0.00694444h; microwave irradiation; |
|
| 90% |
With zinc(II) tetrahydroborate In tetrahydrofuran; lithium hydroxide monohydrate at 20℃; for 1h; |
|
| 88% |
With tetrahydrofuran; dimethylsulfide borane complex In toluene at 0℃; Inert atmosphere; enantioselective reaction; |
Typical procedure for the reduction of prochiral ketones
General procedure: ketonesBH3/SMe2(1.1 ml, 1 M) was added by syringe to a solution ofchiral polyether ligand Poly-6 (0.78 g, 0.1 mmol) in dry THF (5 ml)under nitrogen at 0C. The mixture was stirred for 1 h at 0C andthen a solution of ketone (1 mmol) in dry THF (5 ml) was addeddropwise over a period of 1 h at the same temperature and stirredfor 6 h, the reaction mixture was then quenched by dropwise addi-tion of 10% NH4Cl (5 ml). The alcohol product was isolated byextraction with ethyl acetate (10 ml × 3). The organic phase waswashed with brine, dried over anhydrous sodium sulfate. Afterconcentration by rotatory evaporation, the product was purifiedby column chromatography on silica gel (petroleum ether/ethylacetate 6:1) to afford the corresponding alcohol. The enantiomericexcesses were determined by HPLC with a chiral column (Dai-cel Chiralcel OD-H; eluent, hexane-isopropyl alcohol; UV detector,254 nm). |
| 88% |
With [(η6-p-cymene)ruthenium(II)Cl((C5H4N)-2-CHNC(CH3)3)](hexafluorophosphate); sodium hydroxide In isopropanol at 82℃; for 14h; Inert atmosphere; Schlenk technique; Reflux; |
General procedure: In a typical experiment, the ketone (8.5 mmol), ruthenium(II) complex (0.00425 mmol) and NaOH (3.4 mmol) in 10 mL of 2-propanol were introduced into a Schlenk tube fitted with a reflux condenser and heated to 82 °C in an inert atmosphere. The reaction was then monitored at various time intervals by the use of GC. This was achieved by taking an aliquot, which was first passed through a pad of silica, and then injected (0.1 lL) into the GC. The identity of the alcohol was confirmed by comparison with commercially available (Aldrich Chemical Co) pure samples. |
| 87% |
With Zn(BH4)2(bpy) In acetonitrile at 20℃; for 0.25h; |
|
| 85% |
With hydrogen; iridium at 75℃; for 3.7h; |
|
| 81% |
With C30H28ClN4Os(1+)*F6P(1-); isopropanol; sodium hydroxide at 82℃; for 20h; Inert atmosphere; Schlenk technique; |
|
| 77% |
With C16H9BrMnN3O4; potassium-t-butoxide In isopropanol at 85℃; for 24h; Inert atmosphere; Schlenk technique; |
|
| 60% |
With hydrogenchloride; isopropanol for 0.283333h; Heating; |
|
| 20% |
With sodium isopropanolate In methanol; isopropanol at 25℃; for 24h; Inert atmosphere; |
|
| 1% |
With sodium isopropanolate; acetonitrile In isopropanol at 80℃; for 5h; |
2.2.4 General Procedure forHydrogenation ofKetonesUsing Feimine-mont-K10 astheCatalyst
General procedure: The hydrogenation of ketones was carried out by taking15mg of Feimine-mont-K10 catalyst (19.9mol%),1mmol of ketone, 5mL sodium iso-propoxide (Na-i-OPr),5mL acetonitrile and i-PrOH (5mL) in a round bottomedflask and stirring at 80°C for required time (Table5). Theprogress of the reaction was monitored from time to timeby thin layer chromatography (TLC) using 5% ethylacetate-hexane as the eluent. After completion of the reaction(monitored by GC-MS), the catalyst was separatedby filtration. The filtrate was diluted with water (10mL)and then extracted with ethyl acetate (10mL) followedby washing with brine and dehydrated using anhydrousNa2SO4.The resulting residue was purified by silica gelcolumn chromatography using ethylacetate-hexane (5:95)as the eluent to get the pure products. In order to recyclethe catalyst, it was separated from the reaction mixture bycentrifugation and then washed several times with waterand ethyl acetate after each cycle. After drying at 110°Cin an oven for overnight, the recovered catalyst was subjectedto subsequent runs under same reaction conditions. |
| 100 % Turnov. |
With Li (cyanomethyl)trihydroborate-dioxane In tetrahydrofuran for 1h; Heating; reduction of other carbonyl compounds, reaction with other Li (α-cyanoalkyl)trihydroborates; |
|
|
With hydrogen; nickel at 130 - 140℃; |
|
|
With tris isopropylate aluminium; isopropanol |
|
|
With nickel at 130 - 150℃; Hydrogenation; |
|
|
With copper oxide-chromium oxide at 150℃; Hydrogenation; |
|
|
With natrium |
|
|
With hydrogen; glacial acetic acid; platinum |
|
|
With hydrogen; glacial acetic acid; platinum |
|
|
With platinum Hydrogenation; |
|
|
With kieselguhr; nickel Hydrogenation; |
|
| 100 % Turnov. |
With Li (cyanomethyl)trihydroborate-dioxane In tetrahydrofuran 1.) 30 min room temperature 2.) 1 h reflux; reduction by other Li (α-cyanoalkyl)trihydroborates; |
|
| 38 % Chromat. |
With formic acid at 125℃; for 3h; |
|
| 85 % Chromat. |
With naphthalene; lithium; nickel (II) chloride In tetrahydrofuran at -78℃; for 12h; |
|
|
With potassium phosphate buffer; pig testicular 20β-hydroxysteroid dehydrogenase; NADPH at 37℃; |
|
| 81 % Chromat. |
With 4,4'-di-tert-butylbiphenyl; lithium In tetrahydrofuran at 20℃; for 6h; |
|
| 95 % Turnov. |
With sodium hydroxide; hydrogen In methanol at 20℃; for 48h; |
|
|
With potassium hydroxide; isopropanol at 80℃; for 2h; |
|
|
With isopropanol at 82℃; for 3.5h; |
|
| 96 % Chromat. |
With isopropanol at 89.85℃; for 24h; |
|
|
With [Cp(CO)2(PPh3)W(η1-O=CEt2)]+B(3,5-bis(CF3)phenyl)4; hydrogen In dichloromethane at 23℃; |
|
| 86.0 % Turnov. |
With potassium hydroxide; isopropanol at 80℃; for 2h; |
|
|
In nitrogen |
30 Catalytic Hydrogenation of a Ketone
Example 30 Catalytic Hydrogenation of a Ketone In a glove box a complex of [(1,3-(C6F5C6H12)2C5H3]W(CO)2(IMes)+B(C6F5)4- as prepared in Example 23 (5 mg), and 3-pentanone (160 μL, 5.65 mmol), are placed in a glass tube (125 mL capacity) equipped with a teflon value. The solution is freeze-pump-thawed, frozen again, and the entire tube is submerged in liquid nitrogen. The tube is then filled with about 1.1 atm H2, sealed, and warmed to room temperature. The reaction is carried out at 50° C. in a constant-temperature bath. After 7 days a substantial conversion of the 3-pentanone is hydrogenated to produce, 3-pentanol, an exclusive. Cooling the reaction mixture from about 0° C. to about -78° C. results in the precipitation of the catalyst at the end of the reaction. The solid catalyst can be reused without any loss of activity or selectivity. |
|
In nitrogen |
31 Catalytic Hydrogenation of a Ketone
Example 31 Catalytic Hydrogenation of a Ketone In a glove box a complex of (C5H5)W(CO)2(ImArC6ArF)+B(C6F5)4-) as prepared in Example 24 (5 mg), and 3-pentanone (160 μL, 5.65 mmol), are placed in a glass tube (125 mL capacity) equipped with a teflon value. The solution is freeze-pump-thawed, frozen again, and the entire tube is submerged in liquid nitrogen. The tube is then filled with about 1.1 atm H2, sealed, and warmed to room temperature. The reaction is carried out at 50° C. in a constant-temperature bath. After 7 days a substantial conversion of the 3-pentanone is hydrogenated to produce, 3-pentanol, an exclusive. Cooling the reaction mixture from about 0° C. to about -78° C. results in the precipitation of the catalyst at the end of the reaction. The solid catalyst can be reused without any loss of activity or selectivity. |
|
In nitrogen |
32 Catalytic Hydrogenation of a Ketone
Example 32 Catalytic Hydrogenation of a Ketone In a glove box a complex of (C6H5)W(CO)2(PRC6ArF3)(Et2C=O)+B(C6F5)4- as prepared in Example 25 (5 mg), and 3-pentanone (160 μL, 5.65 mmol), are placed in a glass tube (125 mL capacity) equipped with a teflon value. The solution is freeze-pump-thawed, frozen again, and the entire tube is submerged in liquid nitrogen. The tube is then filled with about 1.1 atm H2, sealed, and warmed to room temperature. The reaction is carried out at 50° C. in a constant-temperature bath. After 7 days a substantial conversion of the 3-pentanone is hydrogenated to produce, 3-pentanol, an exclusive. Cooling the reaction mixture from about 0° C. to about -78° C. results in the precipitation of the catalyst at the end of the reaction. The solid catalyst can be reused without any loss of activity or selectivity. |
|
In complex of (C5H5)W(CO)2(ImArC6ArF)+B(C6F5)4-; nitrogen |
33 Catalytic Hydrogenation of a Ketone
Example 33 Catalytic Hydrogenation of a Ketone In a glove box a complex of (C5H5)W(CO)2(ImArC6ArF)+B(C6F5)4- as prepared in Example 24 (please confirm) (5 mg), and 3-pentanone (160 μL, 5.65 mmol), are placed in a glass tube (125 mL capacity) equipped with a teflon value. The solution is freeze-pump-thawed, frozen again, and the entire tube is submerged in liquid nitrogen. The tube is then filled with about 1.1 atm H2, sealed, and warmed to room temperature. The reaction is carried out at 50° C. in a constant-temperature bath. After 7 days a substantial conversion of the 3-pentanone is hydrogenated to produce, 3-pentanol, an exclusive. Cooling the reaction mixture from about 0° C. to about -78° C. results in the precipitation of the catalyst at the end of the reaction. The solid catalyst can be reused without any loss of activity or selectivity. |
| 100 %Spectr. |
With hydrogen; triethylamine In hexane at 23℃; for 1h; Autoclave; |
|
| 96 %Chromat. |
With isopropanol at 89.84℃; for 1h; Inert atmosphere; |
|
|
With (1,3-bis(2-pyridyloxy)phenyl)aquo rhodium(III) dichloride; potassium hydroxide In isopropanol at 82℃; for 24h; Inert atmosphere; |
|
|
With C51H43ClN3O3P2RuS; isopropanol; potassium hydroxide at 82℃; for 2h; Inert atmosphere; |
|
| 89 %Spectr. |
With [Cp*Ru(CO)2]2(μ-H)}(+)*OTf(-); hydrogen In dichloromethane-d2 at 65℃; for 72h; |
|
|
With hydrogen In ethanol at 49.84℃; |
|
| 88 %Spectr. |
With C51H53ClN3O2P2Ru(1+)*Cl(1-); Cs2CO3; isopropanol at 83℃; for 24h; Inert atmosphere; |
|
|
With (thiophene-2-(N-diphenylphosphino)methylamine)(η6-p-cymene)dichlororuthenium(II); sodium hydroxide In isopropanol for 4h; Reflux; Inert atmosphere; |
4.3. Transfer hydrogenation of ketones
Typical procedure for the catalytic hydrogen transfer reaction: a suspension of metal complexes Ru(II), Rh(I) or Ir(III)(0.005 mmol), NaOH (0.025 mmol) and alkyl ketone (0.5 mmol) in degassed iso-PrOH (5 mL) was refluxed until the reaction is completed. After this time a sample of the reaction mixture is taken, diluted with acetone and analyzed immediately by GC. Yields obtained are related to the residual unreacted ketone. |
|
With methanol; borane-ammonia complex at 20℃; Inert atmosphere; |
5.4. Reactions of ketones and aldehydes with AB in methanol
General procedure: A 0.5 mm NMR tube was charged with ketone or aldehyde (0.2 mmol), AB (0.1 mmol), and deuterated methanol. The tube was covered with a plastic cap and inserted into the NMR machine after shaking. The reaction courses were monitored by 1H and 11B NMR every several minutes (depending on the reaction rates). The typical resonances of the starting materials gradually decreased while new signals of the saturated products appeared. After the ketone or aldehyde disappeared completely in the 1H NMR spectrum, 13C NMR spectrum was recorded. For a large scale reaction in normal methanol, the solvent and all volatile compounds (trimethyl borate and ammonia) were removed by high vacuum after the reaction, and the remaining alcohol was pure to the limit of the NMR with nearly 100% yield. |
|
With glucose dehydrogenase; D-glucose; (R)-specific alcohol dehydrogenase from Candida maris IFO10003; NADH In dimethyl sulfoxide at 30℃; for 17h; aq. phosphate buffer; Enzymatic reaction; |
|
|
With trans-[Ru((PPh2)2NCH2-C4H3O)2Cl2]; potassium hydroxide In isopropanol at 82℃; for 6h; Inert atmosphere; |
|
|
With C56H48As2Cl4N4O2Ru2; isopropanol; potassium hydroxide In isopropanol at 82℃; for 5h; Inert atmosphere; |
Procedure for catalytic transfer hydrogenation of ketones:
General procedure: Under nitrogen atmosphere a mixture containing ketones (1 mmol), the ruthenium catalyst (0.002 mmol), and KOH (0.005 mmol) was heated to reflux in 5 ml of isopropanol for 5 h. The catalyst was removed from the reaction mixture by the addition of diethyl ether followed by filtration and subsequent neutralization with 1 M HCl. The ether layer was filtered through a short path of silica gel by column chromatography. The filtrate was subjected to 1H NMR analysis. |
| 94 %Spectr. |
With formic acid; [(η6-benzene)RuCl(4,4′-dimethoxy-2,2′-bipyridine)]BF4; anhydrous sodium formate In lithium hydroxide monohydrate at 80℃; for 20h; Inert atmosphere; Schlenk technique; |
|
|
With C55H41ClN2O3P2Ru; isopropanol; potassium hydroxide In 1,3-dimethylbenzene at 20 - 82℃; for 4h; Inert atmosphere; |
Typical procedure for transfer hydrogenation of ketones
General procedure: In an oven-dried round bottom flask, were placed ketone (2.4 mmol), catalyst (3 mol), base (12 mol), internal standard (m-xylene, 30 L, 0.24 mmol) and i-PrOH (5 mL) at room temperature. The reaction mixture was heated at 82 °C for the required reaction time under an atmosphere of nitrogen. Aliquots (0.2 mL) were taken at fixed time and the catalyst removed as precipitate from the reaction mixture by the addition of diethyl ether. The organic layer was neutralized with 1 N HCl, washed with water and dried over anhydrous Na2SO4. The combined organic layer passed through a short path of silica gel and then subjected to GCMS analysis. The conversions obtained are related to the residual unreacted ketone and are averages of two runs in the case of all catalytic reactions. |
|
With [C10H6N2{NHPPh2Ru(η6-benzene)Cl2}2]; sodium hydroxide In isopropanol for 2h; Reflux; Inert atmosphere; |
4.3.4 General procedure for the transfer hydrogenation of ketones
General procedure: Typical procedure for the catalytic hydrogen transfer reaction: a solution of complexes [C10H6N2{NHPPh2Ru(η6-benzene)Cl2}2], 1, [C10H6N2{PPh2NHRh(cod)Cl}2], 2 and [C10H6N2{NHPPh2Ir(η5-C5Me5)Cl2}2], 3 (0.005 mmol), NaOH (0.025 mmol) and the corresponding ketone (0.5 mmol) in degassed iso-PrOH (5 mL) were refluxed for 10 min for 1, 1 h for 2 and 3 h for 3. After this period a sample of the reaction mixture was taken off, diluted with acetone and analyzed immediately by GC. Conversions obtained are related to the residual unreacted ketone. |
| 78 %Spectr. |
With trans-RuCl(6,6'-dihydroxyterpyridine)(PPh<SUB>3</SUB>)<SUB>2</SUB>PF<SUB>6</SUB>; potassium-t-butoxide; isopropanol at 80℃; for 12h; Inert atmosphere; Sealed tube; chemoselective reaction; |
|
|
With [Ru(Cy2PNHCH2-C4H3S)(η6-benzene)Cl2]; isopropanol; sodium hydroxide at 82℃; for 3h; Inert atmosphere; Schlenk technique; |
|
|
With cyclopentadienyliron(II) dicarbonyl iodide; 3-ethyl-1-methyl-1H-imidazol-3-ium bromide; potassium hydroxide In isopropanol at 82℃; for 12h; Schlenk technique; Inert atmosphere; |
General procedure for the transfer hydrogenation of ketones
General procedure: The samples were typically prepared as follows: The ketone (2.1mmol), iron(II) metal precursor (0.5mol%), imidazolium salt (1-9, 0.5 mol%) and KOH (0.112g, 0.2M) in 10ml 2-propanol were introduced into a Schlenk tube fitted with a reflux condenser and heated at 82°C in an inert atmosphere. The reaction was then monitored at various time intervals by the use of GC. This was achieved by taking an aliquot which was first passed through a pad of silica and then injected (0.1μl) into the GC with a DB wax polyethylene column (see details above). The corresponding alcohol and acetone were the only products detected in all cases. The identity of the alcohol was assessed by comparison with commercially available (Aldrich Chemical Co.) pure samples. Conversion to the product was calculated from integration of its GC peak relative to that of residual unreacted ketone. |
|
With [Rh(Cy2PNHCH2-C4H3O)(cod)Cl]; isopropanol; sodium hydroxide for 3h; Inert atmosphere; Schlenk technique; Reflux; |
4.2. General procedure for the transfer hydrogenation of ketones
General procedure: Typical procedure for the catalytic hydrogen transfer reaction: a solution of complexes [Rh(Cy2PNHCH2-C4H3O)(cod)Cl], (1),[Rh(Cy2PNHCH2-C4H3S)(cod)Cl], (2), [Ir(Cy2PNHCH2-C4H3O)(η5-C5Me5)Cl2], (3) and [Ir(Cy2PNHCH2-C4H3S)(η5-C5Me5)Cl2], (4)(0.005 mmol), NaOH (0.025 mmol) and the corresponding ketone(0.5 mmol) in degassed iso-PrOH (5 mL) were refluxed until the reactions were completed. After this period a sample of the reactionmixture was taken off, diluted with acetone and analyzed immediately by GC. Conversions obtained are related to the residual unreacted ketone. |
|
With [Ru((Cy2PO)-C7H14N2Cl)(η6-p-cymene)Cl2]Cl; potassium hydroxide In isopropanol for 2h; Inert atmosphere; Schlenk technique; Reflux; |
3.2 Transfer hydrogenation of ketones
General procedure: Typical procedure for the catalytic hydrogen transfer reaction: a solution of the complexes [Ru((Ph2PO)-C7H14N2Cl)(η6-arene)Cl2]Cl and [Ru((Ph2PO)-C7H14N2Cl)(η6-arene)Cl2]Cl {arene: benzene 4, 5; p-cymene 6, 7} (0.005 mmol), KOH (0.025 mmol) and the corresponding ketone (0.5 mmol) in degassed 2-propanol (5 mL) was refluxed until the reactions were completed. Then, a sample of the reaction mixture was taken off, diluted with acetone and analyzed immediately by GC. The conversions are related to the residual unreacted ketone. GC analyses were performed a Shimadzu 2010 Plus Gas Chromatograph equipped with a capillary column (5 % biphenyl, 95 % dimethylsiloxane) (30 m×0.32 mm×0.25 μm). The GC parameters for transfer hydrogenation of the ketones were as follows: initial temperature, 50° C; initial time, hold min 1 min; solvent delay, 4.48 min; temperature ramp 15° C/min; final temperature, 270° C, hold min 5 min; final time, 20.67 min; injector port temperature, 200° C; detector temperature, 200° C, injection volume, 2.0 μL |
|
With [(ruthenium(II))3(2-[(diphenylphosphanyl)({2-[(diphenylphosphanyl)oxy]ethyl})amino]-ethyldiphenylphosphinite)(η6-p-cymene)3Cl6]; isopropanol; sodium hydroxide at 82℃; for 0.666667h; Reflux; |
|
|
With [(ruthenium(II))3(2-[(diphenylphosphanyl)({2-[(diphenylphosphanyl)oxy]ethyl})amino]-ethyldiphenylphosphinite)(η6-p-cymene)3Cl6]; isopropanol; sodium hydroxide at 82℃; Inert atmosphere; Schlenk technique; |
|
|
With palladium on activated carbon; hydrogen In glacial acetic acid at 100℃; for 15h; |
|
|
With [Ru(2,2'-bipyridine)2(1,5-dihydro-2H-cyclopenta[1,2-b:5,4-b′]dipyridine-2-one)](PF6)2; isopropanol; sodium hydroxide at 82℃; for 9h; |
2.2 General procedure for the transfer hydrogenation of ketones
General procedure: A typical procedure for the catalytic hydrogen transfer reaction was as follows: A solution of the complex [Ru(bpy)2L](PF6)2], NaOH (0.025mmol) and the corresponding ketone (0.5mmol) in degassed iso-Pr-OH (5mL) were refluxed until the completion of the reaction. After this period, a sample of the reaction mixture was taken, diluted with acetone and analyzed immediately by GC. Conversions obtained were related to the residual unreacted ketone. The GC parameters were as follows: initial temperature, 110°C; initial time, 1min; solvent delay, 4.48min; temperature ramp 80°C/min; final temperature, 200°C; final time, 21.13min; injector port temperature, 200°C; detector temperature, 200°C; injection volume, 2.0μL. |
|
With Cu2.94Mo6S7.7; hydrogen at 300℃; for 3h; Flow reactor; |
General procedure: The reactions were performed using a conventional continuous-flow micro-reactor operated at atmospheric pressure [10]. Typically, a weighed crystalline cluster sample (30 mg) of CuxMo6S8-δ(x = 2.94, δ≈ 0.3) (1) stored in air was packed in a borosilicate glass tube (3 mm i.d.), andplaced in the center of an electric furnace. The catalyst sample was initially heated from room temperature to a fixed tempera-ture between 250 and 500C over 15 min in a hydrogen stream(2.4 L/h), and then held at this temperature for 45 min. Withoutchanging the temperature, the reaction was initiated by feedingreactant (0.5 mmol/h) into the hydrogen stream using a syringepump. The reaction was monitored every 30 min by sampling thereaction gas (1 mL) via a six-way valve kept at 150C, followedby analysis using an on-line gas-liquid chromatograph (GLC). Thereactor effluent was frozen in an ice-water trap for determination ofmaterial balance and subsequent analysis of the products. Catalyticreactions using the other catalysts were performed in the sameway [4]. |
| 90 %Chromat. |
With potassium hydroxide In isopropanol at 80℃; |
General procedure for the catalytic transfer hydrogenation reaction
General procedure: The substrate (ketone) (2.4mmol), ruthenium catalyst (2.5μmol), and propan-2-ol (5mL) were introduced into a two necked round-bottomed flask fitted with a condenser and heated at 80°C for 15-20min in an open air atmosphere. Then, a solution of KOH (0.05mmol) in 2-propanol (5mL) was introduced to initiate the reaction and it was heated at 80°C. The progress of the reaction was monitored by GC analysis of the samples. |
| 90 %Spectr. |
With C55H45O2P3RuS2; potassium-t-butoxide; triphenylphosphine In isopropanol at 75℃; for 12h; Schlenk technique; Inert atmosphere; |
|
|
With isopropanol at 80℃; for 48h; chemoselective reaction; |
|
|
With tris(pentafluorophenyl)borate; hydrogen In 1,4-dioxane at 100℃; for 90h; Glovebox; Inert atmosphere; |
|
| 90 %Chromat. |
With C20H20ClN2Ru(1+)*F6P(1-); isopropanol; sodium hydroxide at 82℃; for 20h; Inert atmosphere; Schlenk technique; |
1.2.4. general procedure for transfer hydrogenation of ketones
General procedure: In a typical experiment the ketone (8.5 mmol), ruthenium(II) complex (0.00425 mmol) and NaOH (3.4 mmol) in 10 ml 2-propanol were introduced into a Schlenk tube fitted with a reflux condenser and heated to 82 °C in an inert atmosphere. The reaction was then monitored at various time intervals by the use of GC. This was achieved by taking an aliquot which was first passed through apad of silica and then injected (0.1 l) into the GC. The corresponding alcohol was the only product detected in all cases. The identity of the alcohol was confirmed by comparison with commercially available (Aldrich Chemical Co.) pure samples. |
|
With 2,6-bis(3,5-dimethylpyrazoyl)pyridine iron(II) chloride; potassium hydroxide In isopropanol at 82℃; for 48h; Inert atmosphere; |
|
|
With C29H36Cl3IrN2OP(1+)*Cl(1-); isopropanol; sodium hydroxide for 2h; Reflux; Inert atmosphere; Schlenk technique; |
2.2 Transfer hydrogenation of ketones
General procedure: Typical procedure for the catalytic hydrogen transfer reaction: a solution of cataysts (1-chloro-3-(3-methylimidazolidin-1-yl)propan-2-yl diphenylphosphinite chloride) (chloro 4-1,5-cyclooctadiene rhodium(I))], 2 or (1-chloro-3-(3-methylimidazolidin-1-yl)propan-2-yl diphenylphosphinite chloride) (dichloro 5-pentamethylcyclopentadienyl iridium(III))], 3 (0.005mmol), NaOH (0.025mmol) and the corresponding ketone (0.5mmol) in degassed 2-propanol (5mL) were refluxed until the reactions were completed. Then, a sample of the reaction mixture was taken off, diluted with acetone and analyzed immediately by GC. The conversions are related to the residual unreacted ketone. GC analyses were performed on a Shimadzu 2010 Plus Gas Chromatograph equipped with capillary column (5% biphenyl, 95% dimethylsiloxane) (30m×0.32mm×0.25μm). The GC parameters for transfer hydrogenation of ketones were as follows; initial temperature, 50°C; initial time, hold min 1min; solvent delay, 4.48min; temperature ramp 15 °C/min; final temperature, 270°C, hold min 5min; final time, 20.67min; injector port temperature, 200°C; detector temperature, 200°C, injection volume, 2.0μL. |
|
With C22H19Br2N3Ni; isopropanol; potassium hydroxide at 82℃; |
|
|
With C25H26Cl2N2ORu; sodium hydroxide In isopropanol at 82℃; for 5h; |
|
| 96 %Spectr. |
Stage #1: pentan-3-one With phenylsilane In dichloromethane at 25℃; for 5 - 7h;
Stage #2: With sodium hydroxide In chloroform-d1 |
|
|
Stage #1: pentan-3-one With hydrogen at 50℃; for 0.333333h; Inert atmosphere; High pressure;
Stage #2:
Stage #3: |
|
|
With C45H40Cl2N2P2Ru; potassium-t-butoxide; isopropanol at 82℃; |
|
|
With C31H30ClN3ORu; potassium hydroxide In isopropanol at 80℃; for 3h; Inert atmosphere; |
4.6. Typical procedure for the catalytic transfer hydrogenation of ketones
General procedure: In a dry round bottom flask under an atmosphere of nitrogenwere placed an appropriate amount of catalyst 4-6 (0.01 mmol),(0.03 mmol) of KOH and (5.0 mmol) of ketones in 2-propanol(5 mL) was added and the resulting mixture was refluxed for 3 h.After completion of the reaction, the solvent was removed underreduced pressure. The catalyst was removed by the addition of15 mL of petroleum ether followed by filtration and subsequentneutralization with dilute HCl. The combined organic fractionswere dried with anhydrous Na2SO4. Percentage of conversion wasdetermined by GC analysis of the crude mixture and compared withthe authentic samples. |
|
With C18H17N4NiO(1+)*F6P(1-); isopropanol; potassium hydroxide at 82℃; for 6h; Schlenk technique; |
4.3. Catalytic transfer hydrogenation
General procedure: All the samples were prepared as follows: into a Schlenck tube fitted with a condenserand stirrer bar was added the substrate ketone (2.1 mmol), nickel catalyst (0.2 mol%),KOH (2 mmol), and 10 mL 2-propanol. The mixture was heated at 82 °C. Conversion ofthe ketones to corresponding alcohols was monitored using gas chromatography.Aliquots were taken at given time intervals, filtered through a pad of cotton wool andthen injected (0.5 mL) into a GC equipped with a DB1 Wax polyethylene column. Theproduct was identified by comparison with standards purchased from Sigma Aldrich.The conversion was calculated from the respective peak area of each product. |
| 98 %Chromat. |
With acetophenone reductase from Geotrichum candidum NBRC 4597; nadide In isopropanol at 30℃; for 3h; Enzymatic reaction; |
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With [Ru(OAc)(a-PC)2]Br; sodium isopropanolate In isopropanol at 80℃; for 0.333333h; |
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With C56H44Cl2NOP2Ru; potassium hydroxide In isopropanol at 80℃; for 5h; |
2.3. Typical procedure for transfer hydrogenation of ketones
The mixture of a ketone (5.0 mmol) and base (0.03 mmol) containing the catalyst(0.2 mol %), i-PrOH (6 mL) was refluxed for 5 h. After completion of the reaction, thesolvent was removed under reduced pressure. The catalyst was removed by the additionof 15 mL of petroleum ether followed by filtration and subsequent neutralizationwith dilute HCl. The combined organic fractions were dried over anhydrous Na2SO4.Percentage of conversion was determined by GC analysis of the crude mixture andcompared with the authentic samples. |
| 11 %Chromat. |
With 1,3-bis(4-fluorophenyl)imidazolium tetrafluoroborate; isopropanol; potassium hydroxide at 82℃; for 12h; Green chemistry; |
A typical procedure for the transfer hydrogenation reaction is described
General procedure: 1,3-diarylimidazolium salt 1 (0.0105 mmol, 3.6 mg) and KOH (0.112 g, 10 ml, 0.2 M in i-PrOH) were added to a round-bottom flask followed by the addition of cyclohexanone (2.1 mmol, 0.21 mL). The mixture was refluxed at 82 C for 12 h. The reaction progress was monitored by taking aliquots at time intervals which were passed through a pad of silica and injected into a GC. The identities of the products were assessed by comparison of their retention times with commercially available (Aldrich Chemical Co.) samples. The percentage conversions were obtained from integration values of the GC peaks which were related to residual unreacted ketones. |
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With hydrogen In ethanol at 100℃; for 4h; Autoclave; |
2.5. Catalytic hydrogenation reactions
General procedure: Catalytic hydrogenation of carbonyl compounds was completed in a 50 mL stainless steel autoclave lined with polytetrafluoroethylene. Inthe typical process, 15.0 mg catalyst and 1.0 mmol substrate were dispersed in 5.0 mL ethanol and then sealed in the autoclave. The pressure reactor was purged 3 times with nitrogen in order to remove the internal air and then purged 3 times with hydrogen. Finally, the reaction device was stirred at a certain reaction temperature for several hours. The liquid mixture was separated by filtration and analyzed by gas chromatograph (GC). |
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With bis(cyclopentadienyl) iron(II); C34H28Br2Mn2N6O7; phenol In tetrahydrofuran-d8 Electrolysis; Glovebox; chemoselective reaction; |
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| 82 %Chromat. |
With fac-[Mn((1,2-bis(di-isopropylphosphino)ethane))(CO)3(CH2CH2CH3)]; hydrogen In diethyl ether at 25℃; for 24h; Inert atmosphere; Glovebox; Autoclave; |
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| 25 %Spectr. |
With potassium isopropoxide; [UO2(OTf)2]; isopropanol at 80℃; for 15h; Inert atmosphere; Schlenk technique; |
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With [chloro(η4-1,5-cyclooctadiene)(1-furan-2-ylethyldiphenylphosphinite)rhodium(I)]; potassium hydroxide In isopropanol for 18h; Reflux; |
2.3. General procedure for the transfer hydrogenation of ketones
General procedure: A typical procedure for the catalytic hydrogen transfer reaction is given below: a solutionof pre-catalysts (2-5) (0.0025mmol), KOH (0.0125mmol), and the respective ketone(0.5mmol) in degassed 2-propanol (5mL) was refluxed until the reactions were completed.Then, a sample of the reaction mixture was taken off, diluted with acetone, and analyzedimmediately by GC. The conversions are related to the residual unreacted ketone. |
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