Preparation of Multisubstituted Enamides via Rhodium-Catalyzed Carbozincation and Hydrozincation of Ynamides
摘要:
Rhodium-catalyzed carbozincation of ynamides using diorganozinc reagents or functionalized organozinc halides is described. Using a tri(2-furyl)phosphine-modified rhodium catalyst, the reaction course is altered to hydrozincation when diethylzinc is employed as the organozinc reagent. Trapping of the alkenylzinc intermediates produced in these reactions in further functionalization reactions is possible. Collectively, these processes enable access to a range of multisubstituted enamides in stereo- and regiocontrolled fashion.
Preparation of Multisubstituted Enamides via Rhodium-Catalyzed Carbozincation and Hydrozincation of Ynamides
作者:Benoit Gourdet、Mairi E. Rudkin、Ciorsdaidh A. Watts、Hon Wai Lam
DOI:10.1021/jo901658v
日期:2009.10.16
Rhodium-catalyzed carbozincation of ynamides using diorganozinc reagents or functionalized organozinc halides is described. Using a tri(2-furyl)phosphine-modified rhodium catalyst, the reaction course is altered to hydrozincation when diethylzinc is employed as the organozinc reagent. Trapping of the alkenylzinc intermediates produced in these reactions in further functionalization reactions is possible. Collectively, these processes enable access to a range of multisubstituted enamides in stereo- and regiocontrolled fashion.
Catalytic Asymmetric Dihydroxylation of Enamides and Application to the Total Synthesis of (+)-Tanikolide
作者:Benoit Gourdet、Hon Wai Lam
DOI:10.1002/anie.201004328
日期:2010.11.8
Asymmetricdihydroxylation of β,β′‐ disubstituted enamides afforded chiral tertiary‐alcohol‐containing α‐hydroxyaldehydes and 1,2‐diols with high enantioselectivity (see scheme). This method was applied to the total synthesis of the antifungal natural product (+)‐tanikolide, as well as the synthesis of an intermediate en route to (S)‐oxybutynin.