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.
Rhodium(II) (S)-N-(arylsulfonyl)prolinate catalyzed asymmetric insertions of vinyl- and phenylcarbenoids into the SiH bond
作者:Huw M.L. Davies、Tore Hansen、James Rutberg、Paul R. Bruzinski
DOI:10.1016/s0040-4039(97)00205-0
日期:1997.3
Allylsilanes or benzylsilanes of high enantiomeric purity (77–95% ee) are formed from the rhodium(II) (S)-N-[p-(dodecylphenyl)sulfonyl]prolinate (1) catalyzed decomposition of vinyldiazomethanes or phenyldiazomethanes in the presence of dimethylphenylsilane (3).
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