Enantioselective acyl transfer catalysts and their use in kinetic resolution of alcohols and desymmetrization of meso-diols
申请人:Birman Vladimir
公开号:US20050256150A1
公开(公告)日:2005-11-17
Novel enantioselective acylation catalysts comprising chiral derivatives of DHIP and DHIQ, having the following representative general structures are disclosed:
These new compounds are useful for resolving racemates or further enhancing the enantiomeric excess of an enantiomerically enriched composition and for desymmetrizing meso compounds.
A chemoselective 1,2-reduction of cycloalkyl vinyl ketones via asymmetric transfer hydrogenation is described. The reduction proceeded smoothly with a chiral diamine ruthenium complex as a catalyst and a HCOOH–NEt3 azeotrope as both a hydrogen source and solvent under mild conditions. A wide range of 1-cycloalkyl chiral allylicalcohols were obtained in good yields and up to 87% ee. It was found that
A new strategy has been established for the kineticresolution of racemic allylic alcohols through a palladium/sulfonyl‐hydrazide‐catalyzed asymmetric OH‐substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]2, 4 mol % (S)‐SegPhos, and 10 mol % 2,5‐dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than
Highly Enantio- and Diastereoselective Tandem Generation of Cyclopropyl Alcohols with up to Four Contiguous Stereocenters
作者:Hun Young Kim、Alice E. Lurain、Patricia García-García、Patrick J. Carroll、Patrick J. Walsh
DOI:10.1021/ja0539239
日期:2005.9.28
Three highly enantio- and diastereoselective one-pot procedures for the synthesis of cyclopropyl and iodocyclopropyl alcohols with up to four contiguous stereocenters are reported. Route 1 involves asymmetric addition of an alkylzinc reagent to an enal followed by diastereoselective cyclopropanation. Route 2 parallels route 1, except that iodoform is used to generate the zinccarbenoid, and the products
Facile synthesis of chiral isopropyl carbinols with high enantiomeric excess via catalytic enantioselective addition of diisopropylzinc to aldehydes
作者:Weon Ki Yang、Byung Tae Cho
DOI:10.1016/s0957-4166(00)00253-6
日期:2000.7
Highly effective syntheses of chiral alkyl and aryl isopropyl carbinols with highenantiomericexcess (94–98% ee) via catalytic enantioselective addition of diisopropylzinc to aldehydes have been developed.