Enantioselective addition of organozinc reagents to carbonyl compounds catalyzed by a camphor derived chiral γ-amino thiol ligand
作者:Hsyueh-Liang Wu、Ping-Yu Wu、Ying-Ni Cheng、Biing-Jiun Uang
DOI:10.1016/j.tet.2015.07.038
日期:2016.5
synthesis of the chiral camphor derived γ-amino thiol ligand 17 and its application in catalytic enantioselective carbon-carbon forming reactions through the addition of organozinc reagents to carbonyl compounds is described. The catalytic activity and enantioselectivity of ligand 17 is demonstrated in the enantioselective addition of various organozinc reagents to aldehydes and ketoesters, offering the corresponding
SYNTHESIS, STRUCTURE AND USE OF BISOXAZOLIDINES FOR ASYMMETRIC CATALYSIS AND SYNTHESIS
申请人:Wolf Christian
公开号:US20070265255A1
公开(公告)日:2007-11-15
One aspect of the invention relates to chiral bisoxazolidines and their use in asymmetric catalysis. The chiral bisoxazolidines are a novel class of compounds that is expected to find multiple applications, for example, in asymmetric synthesis. For example, a bisoxazolidine ligand enabled the catalytic enantioselective alkynylation and alkylation of a range of aromatic and aliphatic aldehydes, generating chiral propargylic alcohols and secondary alcohols in high yields and enantiomeric excess.
The asymmetric addition of lithium acetylides to carbonylcompounds in the presence of a chiral lithium binaphtholate catalyst was developed. A procedure involving the slow addition of carbonylcompounds to lithium acetylides improved the enantioselectivity. This reaction afforded diverse chiral secondary and tertiary propargylic alcohols in high yields and with good to high enantioselectivities.
Enantioselective alkynylation of aldehydes and ketones was accomplished using trimethoxysilylalkynes as alkynylating reagents and lithium 3,3′-diphenylbinaphtholate as a catalyst. Optically active propargylic alcohols were obtained in good to high chemical yields and enantioselectivities. Alkynylation of acetylpyridines afforded biologically active pyridyl propargylic alcohols in good enantioselectivities
作者:M. Mark midland、Alfonso tramontano、Aleksander kazubski、Richard S. graham、David J.S. tsai、Daniel B. cardin
DOI:10.1016/s0040-4020(01)82422-4
日期:1984.1
Propargyl ketones are readily reduced by the asymmetric reducing agent B-3-pinanyl-9- borabicyclo[3.3.1]-nonane (Alpine-borane). The reagent prepared from (+)-α-pinene and 9-BBN provides the R enantiomer while the S enantiomer can be obtained from (-)-α-pinene. Alternatively the S enantiomer can be prepared from the reagent derived from 9-BBN and the benzyl ether of nopol (6,6-dimethyl-bicyclo[3.11