在我们对 1-炔基醚的低温重排研究的扩展中,我们在本文中描述了原位形成的炔丙基炔基醚到联烯基乙烯酮的 [3,3]-σ 重排,其提供复杂的叔丁基-(2 E ,4 Z )-dienoates 2在加入叔丁醇后收率高。类似地,原位形成的炔丙基锂基炔基醚的 sigmatropic 重排在甲醇加成后产生甲基-(2 Z ,4 Z )-二烯酸酯4或在醛或酮加成丙二烯基炔诺酸酯中间体时产生不饱和内酯6 。
[3,3]-Sigmatropic Rearrangement/5-<i>exo</i>-<i>dig</i> Cyclization Reactions of Benzyl Alkynyl Ethers: Synthesis of Substituted 2-Indanones and Indenes
作者:Armen A. Tudjarian、Thomas G. Minehan
DOI:10.1021/jo200271s
日期:2011.5.6
Substituted benzyl alkynyl ethers, prepared from the corresponding α-alkoxy ketones in a two-step sequence involving enol triflate formation and KOtBu-induced E2 elimination, undergo [3,3]-sigmatropic rearrangement/intramolecular 5-exo-dig cyclization at 60 °C to form substituted 2-indanones in good overall yields. 1,3-cis-Disubstituted-2-indanones are formed preferentially when the benzylic substituent
取代的苄基的炔醚,从在两步骤序列相应的α -烷氧基酮涉及烯醇三氟甲磺酸形成和KO制备吨卜诱导E2消除,经历[3,3] -sigmatropic重排/分子内-5-外-挖环化在60 °C 以良好的总产率形成取代的 2-茚满酮。当苄基取代基R 1较大时,1,3-顺式-二取代-2-茚满酮优先形成。取代的茚可以通过霍纳-沃兹沃思-埃蒙斯反应以高产率从 2-茚满酮制备。
Synthesis of Highly Substituted Quinolines via a Tandem Ynamide Benzannulation/Iodocyclization Strategy
作者:Thomas P. Willumstad、Paul D. Boudreau、Rick L. Danheiser
DOI:10.1021/acs.joc.5b01648
日期:2015.12.4
A two-stage “tandem strategy” for the regiocontrolled synthesis of very highly substitutedquinolines is described. Benzannulation based on the reaction of cyclobutenones or diazo ketones with N-propargyl-substituted ynamides proceeds via a cascade of several pericyclic reactions to generate multiply substitutedaniline derivatives. In the second stage of the tandem strategy, triflate derivatives of
A benzannulation strategy for the synthesis of phenols and heteroaromatic compounds based on the reaction of (trialkylsilyl)vinylketenes with lithium ynolates
作者:Wesley F. Austin、Yongjun Zhang、Rick L. Danheiser
DOI:10.1016/j.tet.2007.10.113
日期:2008.1
(Trialkylsilyl)vinylketenes react with lithium ynolates to generate 3-(oxido)dienylketenes, which undergo rapid 6π-electrocyclization. The ultimate products of this benzannulation are highly substituted resorcinol monosilyl ethers, which are formed via a [1,3] carbon to oxygen silyl group shift. Further transformations of the benzannulation products are described providing efficient access to ortho-benzoquinones
Synthesis of Alkynyl Ethers and Low-Temperature Sigmatropic Rearrangement of Allyl and Benzyl Alkynyl Ethers
作者:Juan R. Sosa、Armen A. Tudjarian、Thomas G. Minehan
DOI:10.1021/ol802147h
日期:2008.11.6
transformed into 1-alkynyl ethers 5 by a two-step procedure involving formation of the enol triflate or phosphate and base-induced elimination. Performing the same reaction sequence with allylic alcohols (R2OH, R2 = allyl) furnishes instead gamma,delta-unsaturated carboxylic acid derivatives 6, derived from [3,3]-sigmatropic rearrangement of the intermediate allyl alkynyl ethers at -78 degrees C and trapping