Asymmetric Dehydrative Cyclization of ω-Hydroxy Allyl Alcohols Catalyzed by Ruthenium Complexes
作者:Shinji Tanaka、Tomoaki Seki、Masato Kitamura
DOI:10.1002/anie.200904671
日期:2009.11.9
New axially chiral ligands and their allyl esters have been designed and synthesized. The combination of these ligands with [CpRu(CH3CN)3]PF6 has realized highly efficient intramolecular dehydrative cylization of ω‐hydroxy allylalcohols, to give α‐alkenyl‐substituted cyclic ethers with up to greater than 99:1 enantiomeric ratio without activation of the allylic moieties (see scheme; Cp=cyclopentadienyl
and low E factor. This success can be ascribed to the higher reactivity of allylic alcohols as compared with the allyl ester products in soft Ru/hard Brønstead acid combined catalysis, which can function under slightly acidic conditions unlike the traditional Pd-catalyzed system. Detailed analysis of the stereochemical outcome of the reaction using an enantiomerically enriched D-labeled substrate
LIGAND FOR ASYMMETRIC SYNTHESIS CATALYST, AND PROCESS FOR PRODUCTION OF ALPHA-ALKENYL CYCLIC COMPOUND USING SAME
申请人:Kitamura Masato
公开号:US20120220780A1
公开(公告)日:2012-08-30
Disclosed are: a ligand for an asymmetric synthesis catalyst; and a process for producing an α-alkenyl cyclic compound using the ligand. Specifically disclosed are: a ligand for an asymmetric synthesis catalyst, which is represented by any one of formulae (1) to (4) [wherein R
1
represents —Cl or —Br; R
2
represents —CH
3
or —CF
3
; and R
3
represents —CH
2
—CH═CH
2
or —H]; and a process for producing an α-alkenyl cyclic compound using the ligand.