1-phenylpropan-1-ol

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Under ice cooling, to a solution of 1-phenyl-1-propanol (1.0 g, 7.34 mmol) and N-ethyldiisopropylamine (1.42 g, 11.01 mmol) in dichloromethane (10 ml) was added methanesulfonyl chloride (690 μl, 8.81 mmol), and the mixture was stirred at room temperature for 5 hours. The reaction mixture was diluted with saturated aqueous solution of sodium bicarbonate and extracted with ethyl acetate. The extract was washed with saturated brine, dried over magnesium sulfate, and solvent was distilled off under reduced pressure. The residue was purified by silica gel chromatography (eluent:ethyl acetate/hexane:5/1) to give 1-chloro-1-phenylpropane (610 mg, 54%) as pale yellow liquid. extracted with ethyl acetate The extract was washed with saturated brine dried over magnesium sulfate, and solvent was distilled off under reduced pressure The residue was purified by silica gel chromatography (eluent:ethyl acetate/hexane:5/1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Under ice cooling, to a solution of 1-phenyl-1-propanol (1.0 g, 7.34 mmol) and N-ethyldiisopropylamine (1.42 g, 11.01 mmol) in dichloromethane (10 ml) was added methanesulfonyl chloride (690 μl, 8.81 mmol), and the mixture was stirred at room temperature for 5 hours. The reaction mixture was diluted with saturated aqueous solution of sodium bicarbonate and extracted with ethyl acetate. The extract was washed with saturated brine, dried over magnesium sulfate, and solvent was distilled off under reduced pressure. The residue was purified by silica gel chromatography (eluent:ethyl acetate/hexane:5/1) to give 1-chloro-1-phenylpropane (610 mg, 54%) as pale yellow liquid. extracted with ethyl acetate The extract was washed with saturated brine dried over magnesium sulfate, and solvent was distilled off under reduced pressure The residue was purified by silica gel chromatography (eluent:ethyl acetate/hexane:5/1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: As can be seen from Table 3, the electronic properties of the substituents on the phenyl ring of the ketone changed the reduction rate but had less effect on the enantioselectivity (18-33%). An acetophenone substituted in the para position by an electron releasing group, such as 4′-methyl and 4′-methoxy, is reduced more slowly than acetophenone (entries 3, 8 and 9). The chloro substituted acetophenones are all reduced faster, especially for the ortho position (entries 3-7). This trend is opposite to the generally observed trend for Noyori's transfer hydrogenation catalysts in which an ortho-Cl substitution decreases the rate of the reduction (S. Hashiguchi, A. Fujii, J. Takehara, T. Ikariya, R. Noyori, J. Am. Chem. Soc. 1995, 117, 7562). The catalyst (iii) with KOtBu is also efficient for the transfer hydrogenation of propiophenone, 2-acetonaphthone, benzophenone, benzylacetone, benzaldehyde and N-benzylideneaniline (entries 11-15). The hydrogenation of propiophenone gave 1-phenylpropanol in 61% e.e (S) (entry 10). The more difficult ketimine N-phenyl-(1-phenylethylidene)amine (Ph-CMe=N-Ph) was only partially reduced (<5%) after 18 h under the same conditions (entry 16), while cyclohexanone was not hydrogenated (entry 17). Transfer hydrogenation of unsaturated ketones was complicated by some reduction of the C═C double bond (Scheme 2).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 0.301 g (1 mmol) of (3R)-4-(4-toluenesulfonyl)thiomorpholine-3-carboxylic acid, 0.204 g (1.5 mmol) of phenylpropanol, 0.088 g (0.33 mmol) of CAS, 0.227 g (1.2 mmol) of DCC and 0.04 g (0.33 mmol) of DMAP were dissolved in 15 mL of CH2Cl2. The mixture was stirred for 24 h at room temperature. The solid was filtrated and the solvent was evaporated. The residual was dissolved in a suitable amount of ethyl acetate (20 ml) and then the mixture was filtered to remove insoluble substance. The ethyl acetate was added to 60 ml and then the liquid was washed with 10% NaHCO3 solution, saturated NaCl solution and dried over Na2SO4. After the drying agent was removed and part of ethyl acetate was evaporated, the crude product was purified by flash column chromatography (eluent: ethyl acetate:cyclohexane=2:1) to obtain the product as a oil (0.27 g). The solid was filtrated the solvent was evaporated The residual was dissolved in a suitable amount of ethyl acetate (20 ml) the mixture was filtered to remove insoluble substance The ethyl acetate was added to 60 ml the liquid was washed with 10% NaHCO3 solution, saturated NaCl solution dried over Na2SO4 After the drying agent was removed part of ethyl acetate was evaporated the crude product was purified by flash column chromatography (eluent: ethyl acetate:cyclohexane=2:1)