Rhodium(I)-Catalyzed [4+1] Cycloaddition Reactions of α,β-Unsaturated Imines with Terminal Alkynes for the Preparation of Pyrrole Derivatives
作者:Akio Mizuno、Hiroyuki Kusama、Nobuharu Iwasawa
DOI:10.1002/anie.200904402
日期:2009.10.19
Rhodium vinylidene intermediates are characteristic for the title reaction (see scheme; coe=cyclooctene, cy=cyclohexyl). This reaction proceeds by the nucleophilic addition of the nitrogen atom of the imine to the rhodium vinylidene complex to give a zwitterionic intermediate, which undergoes intramolecular cyclization to afford the corresponding pyrrole.
1-Lithio-1-benzenesulfinyl-2-trimethylsilylethane as a 2-trimethylsilylvinyl anion equivalent in reactions with aldehydes, ketones and epoxides
作者:C-N. Hsiao、H. Shechter
DOI:10.1016/s0040-4039(00)81928-0
日期:1983.1
Aldehydes, ketones and epoxides give adducts with 1-lithio-1-benzenesulfinyl-2-trimethylsilylethane which upon neutralization eliminate benzenesulfenic acid efficiently at 76°C to yield trans-3-(trimethylsilyl)allyl alcohols and trans-4-(trimethylsilyl)-3-alken-1-ols.
Trans-3-silyl allylic alcohols via the brown vinylation
作者:Anil M. Rane、Jaime Vaquer、Juan C. Colberg、John A. Soderquist
DOI:10.1016/0040-4039(94)02422-8
日期:1995.2
The addition of representative aldehydes to trans-vinylborane 1 provided pure trans-3-silylallylicalcohols 2 in excellent yields. The combination of dehydroborylation and insertion leads to the novel dihydroisobenzofuran 7.
[2,3]-Wittig Rearrangement of Enantiomerically Enriched 3-Substituted 1-Propenyloxy-1-phenyl-2-propen-1-yl Carbanions: Effect of Heteroatoms and Conjugating Groups on Planarization of an α-Oxy-Benzylcarbanion through a Double Bond
Don't get trapped: The effect of conjugating electron‐withdrawing groups and α‐anion‐stabilizing heteroatom substituents on configurational stability of chiral carbanions through a double bond was examined on the basis of extent of chirality transfer in intramolecular trapping in [2,3]‐Wittig rearrangement of chiral 3‐substituted 1‐propenyloxy‐1‐phenyl‐2‐propen‐1‐yl carbanions (see scheme).
(Z)-1-Silyl-2-stannylethenes were stereoselectively synthesized by silastannation of ethyne, catalyzed by a palladium/tert-alkyl isocyanide catalyst, and the synthetic utilities were demonstrated by their transformations.