Gold-Catalyzed Formation of Oxonium Ions from Enynes and Their Intra- and Intermolecular Trapping with Allylsilanes
作者:Jingwei Li、Xiaoguang Liu、Daesung Lee
DOI:10.1021/ol203206k
日期:2012.1.6
Gold-catalyzed ringclosure of 1,5-enyne containing a silyl ether at the allylic position induces a skeletal rearrangement to form an oxonium intermediate, which then undergoes a smooth allylation in both an intra- and intermolecular manner. In the intramolecularallyltransfer, the additive alcohol becomes positioned on the silicon of the silyl ether by forming a new Si–OR bond, whereas, in the intermolecular
Cyclizations of Substituted Benzylidene-3-alkenylamines: Synthesis of the Tricyclic Core of the Martinellines
作者:Kristine E. Frank、Jeffrey Aubé
DOI:10.1021/jo990843c
日期:2000.2.1
the formation of different heterocycles including iminodibenzo[b,f][1,5]diazocines, hexahydropyrido[1, 2-c]quinazolin-6-ones, tetrahydropyrrolo[1,2-c]quinazolin-5-ones, 2-arylpiperidines, and 2-arylpyrrolidines. Tetrahydropyrrolo[1, 2-c]quinazolin-5-one 54, obtained via this new methodology, was used as an intermediate in the synthesis of the tricyclic ring system (65) of the martinellines.
Remote Control of Diastereoselectivity in Intramolecular Reactions of Chiral Allylsilanes
作者:Weston R. Judd、Sooho Ban、Jeffrey Aubé
DOI:10.1021/ja063411+
日期:2006.10.1
During investigations of cyclization reactions between chiral allylsilanes and N-acyliminiumions, it was discovered that a suitably positioned benzyloxy group on the allylsilane component caused a reversal in the diastereoselectivity of these reactions relative to that normally observed with alkyl-substituted allylsilanes. This effect was subsequently observed in two other reaction types. Investigations
Silicon directed N-acyliminium ion cyclizations. Highly selective syntheses of (.+-.)-isoretronecanol and (.+-.)-epilupinine
作者:Henk Hiemstra、Michiel H. A. M. Sno、Robert J. Vijn、W. Nico Speckamp
DOI:10.1021/jo00221a011
日期:1985.10
Lewis acid supported reactions of 1,3-bis(silyl)allyl compounds with epoxides — inter- and intramolecular versions
作者:Anette Nowak、Oliver Bolte、Ernst Schaumann
DOI:10.1016/s0040-4039(97)10675-x
日期:1998.2
Easily available 1,3-bis(silyl)allyl compounds react with epoxides under Lewis acid catalysis to give interesting synthetic building blocks. The course of reaction depends on the stabilization of cationic intermediates by the silicon beta-effect. (C) 1998 Elsevier Science Ltd. All rights reserved.