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• 2039-87-4 2-chlorostyrene 

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• 13524-04-4 (R)-1-(o-chlorophenyl)ethanol 

Relevant academic research and scientific papers

Highly enantioselective hydrosilylation of aromatic alkenes

Currently, the most effective and economic way to convert an alkene into an optically active alcohol is the two-step sequence: hydrosilylation/oxidation. Much work has been devoted to elucidating effective catalysts for this process, but hitherto only one effective and highly stereoselective process has been available. Herein we present a novel catalytic system for the asymmetric hydrosilylation of aromatic alkenes, giving the products in high yields and with the highest enantioselectivity (up to 99% ee) ever observed for this reaction. The reaction works efficiently for a variety of substituted aromatic alkenes, giving access after Tamao oxidation to almost optically pure benzylic alcohols in high yields. Copyright

Asymmetric hydrosilylation of styrenes by use of new chiral phosphoramidites

New chiral phosphoramidites were synthesized from chiral unsymmetrical amines and BINOL in good yields. Enantioselective hydrosilylation of styrenes with trichlorosilane in the presence of palladium complexes of these ligands provided chiral silanes in medium to high yields. Oxidation of these chiral silanes with hydrogen peroxide gave the corresponding chiral secondary alcohols in up to 97% ee. Georg Thieme Verlag Stuttgart.

Asymmetric palladium-catalyzed hydrosilylation of styrenes using efficient chiral spiro phosphoramidite ligands

Asymmetric hydrosilylation of styrene derivatives with trichlorosilane in the presence of palladium complexes of chiral spiro phosphoramidites provided 1-aryl-1-silylalkanes as single regioisomers in high yields, which have been oxidized with hydrogen peroxide to give the corresponding chiral alcohols in up to 99.1% ee.

Asymmetric hydrosilylation of styrenes catalyzed by palladium-MOP complexes: Ligand modification and mechanistic studies

In the palladium-catalyzed asymmetric hydrosilylation of styrene (3a) with trichlorosilane, several chiral monophosphine ligands, (R)-2-diarylphosphino-1,1′-binaphthyls (2a-g), were examined for their enantioselectivity. The highest enantioselectivity was observed in the reaction with (R)-2-bis[3,5-bis(trifluoromethyl)phenyl]phosphino-1, 1′-binaphthyl (2g), which gave (S)-1-phenylethanol (5a) of 98% ee after oxidation of the hydrosilylation product, 1-phenyl-1-(trichlorosilyl)ethane (4a). The palladium complex of 2g also efficiently catalyzed the asymmetric hydrosilylation of substituted styrenes on the phenyl ring or at the β position to give the corresponding chiral benzylic alcohols of over 96% ee. Deuterium-labeling studies on the hydrosilylation of regiospecifically deuterated styrene revealed that β-hydrogen elimination from 1-phenylethyl(silyl)palladium intermediate is very fast compared with reductive elimination giving hydrosilylation product when ligand 2g is used. The reaction of o-allylstyrene (9) with trichlorosilane catalyzed by (R)-2g/Pd gave (1S,2R)-1-methyl-2-(trichlorosilylmethyl)indan (10) (91% ee) and (S)-1-(2-(propenyl)phenyl)-1-trichlorosilylethanes (11a and 11b) (95% ee). On the basis of their opposite configurations at the benzylic position, a rationale for the high enantioselectivity of ligand 2g is proposed.

Regio- and Enantioselective Hydrosilylation of 1-Arylalkenes by Use of Palladium-MOP Catalyst

Hydrosilylation of styrenes bearing β-substituents with trichlorosilane was catalyzed by a palladium complex (0.1 mol percent) coordinated with (R)-2-methoxy-2'-diphenylphosphino-1,1'-binaphthyl ((R)-MeO-MOP) to give high yields of optically active 1-aryl-1-silylalkanes (80-85percent ee) as single regioisomers.The resulting silanes were readily converted into the corresponding optically active alcohols (80-99percent yield).