Regioselective Radical Bromoallylation of Allenes Leading to 2-Bromo-Substituted 1,5-Dienes
作者:Takashi Kippo、Takahide Fukuyama、Ilhyong Ryu
DOI:10.1021/ol201395p
日期:2011.8.5
regioselective radical bromoallylation of allenes proceeded efficiently in the presence of AIBN as a radical initiator to give 2-bromo-substituted 1,5-dienes in excellent yields. The addition of a bromine radical took place regioselectively onto the central carbon of allenes generating a stable allyl radical, which underwent addition/β-fragmentation reactions with allylbromides. The products could be
Gold(<scp>i</scp>)-catalysed synthesis of conjugated trienes
作者:Maximillian S. Hadfield、Ai-Lan Lee
DOI:10.1039/c0cc04217j
日期:——
Gold(I)-catalysed reaction between cyclopropenes and furans produces functionalised conjugated trienes. The reaction is mild, facile and proceeds with very low catalyst loadings.
作者:Dietmar Seyferth、Robert L. Lambert、Michel Massol
DOI:10.1016/s0022-328x(00)89503-0
日期:1975.4
A number of α-bromocyclopropyllithium reagents have been prepared at low temperature (−90° to −100°) in THF or THF/Et2O medium by reaction of n-butyllithium with the respective gem-dibromocyclopropane. Reactions of these new lithium reagents with concentrated HCl, trimethylchlorosilane, dimethyldichlorosilane, trimethyltin chloride, dimethyltin dichloride, dimethyldichlorogermane, trimethyllead bromide
通过正丁基锂与相应的宝石-二溴环丙烷的反应,已在THF或THF / Et 2 O介质中于低温(-90°至-100°)下制备了多种α-溴环丙基锂试剂。描述了这些新的锂试剂与浓盐酸,三甲基氯硅烷,二甲基二氯硅烷,三甲基氯化锡,二甲基锡二氯化物,二甲基二氯锗烷,三甲基溴化铅,氯化汞和一些其他有机金属卤化物的反应。的一种新的异构化顺式-7-溴-反-7- lithionorcarane到反-7-溴-顺-7- lithionorcarane,通过稍微过量的7,7- dibromonorcarane的存在引起的,进行说明。
Generation and electrophilic substitution reactions of 3-lithio-2-methyleneaziridines
作者:Cyril Montagne、Natacha Prévost、Jason J. Shiers、Gildas Prié、Sabitur Rahman、Jerome F. Hayes、Michael Shipman
DOI:10.1016/j.tet.2006.06.083
日期:2006.9
2-Methyleneaziridinyl anions can be produced by selective deprotonation of the parent aziridine at C-3 using sec-BuLi/TMEDA. Subsequent reaction with a wide variety of electrophiles including MeI, ICH2CH2CH2CH2Cl, PhCH2Br, allyl bromide, Me3SiCl, Bu3SnCl, PhCHO and Ph2CO provides the corresponding C-3 substituted derivatives in moderate to good yields (43-91%). In the case of homochiral methyleneaziridines bearing an (S)-alpha-methylbenzyl group on nitrogen, high levels of diastereocontrol (up to 90%de) can be achieved in this lithiation/alkylation sequence. (c) 2006 Elsevier Ltd. All rights reserved.