Vinylogous Aldol Products from Chiral Crotylsilanes Obtained by Enantioselective Rh(II) and Cu(I) Carbenoid Si−H Insertion
摘要:
Enantioenriched homoallylic ethers containing a alpha,beta-unsaturated ester (syn-vinylogous aldol products) were directly accessed by Lewis acid catalyzed crotylation utilizing chiral silane 2. The reagents were prepared by enantioselective Si-H Insertion to an alpha-diazovinylacetates using Davies' Rh-2(DOSP)(4) catalyst or chiral Cu(I) Schiff base complex.
Total Synthesis of (−)-Virginiamycin M<sub>2</sub>: Application of Crotylsilanes Accessed by Enantioselective Rh(II) or Cu(I) Promoted Carbenoid Si–H Insertion
作者:Jie Wu、James S. Panek
DOI:10.1021/jo202119p
日期:2011.12.16
A stereoselective synthesis of the antibiotic (−)-virginiamycin M2 is detailed. A convergent strategy was utilized that proceeded in 10 steps (longest linear sequence) from enantioenriched silane (S)-15. This reagent, which was prepared via a Rh(II)- or Cu(I)-catalyzed carbenoid Si–H insertion, was used to introduce the desired olefin geometry and stereocenters of the C1–C5 propionate subunit. A modified