A palladium-catalyzed process to construct oxazoles and oxazolines with broad functional-group tolerance has been developed, and the method introduces difluoromethyl groups into heterocycles in a one-pot fashion. This system uses a carbonyl oxygen as the acceptor for the addition of a vinylpalladium intermediate to achieve the cyclization. Oxazoline derivatives are generated as the Z-isomer with high
catalyzing the alkynes hydrocarbation of allenes (AHA) giving (E)-1,3-enynes with high yields, atom economy, and high regio-/stereoselectivities. We devised new efficient conditions and expanded the substrate scope. Experimental and computational studies support a nonorthodox PdII/PdIV catalytic cycle involving an oxidative addition triggered by a stereodeterminant H+ transfer. This reaction is leveraged
Pd II和Cu I协同催化具有高收率,原子经济性和高区域/立体选择性的丙二烯(AHA)炔烃加氢生成(E)-1,3-炔烃。我们设计了新的有效条件并扩大了基材范围。实验和计算研究支持非正统的Pd II / Pd IV催化循环,该循环涉及由立体决定簇H +转移触发的氧化加成。该反应在1,3-二烯的立体选择性合成的新策略中得到利用。
Gold‐Catalyzed Stereoselective Domino Cyclization/Alkynylation of
<i>N</i>
‐Propargylcarboxamides with Benziodoxole Reagents for the Synthesis of Alkynyloxazolines
作者:Ximei Zhao、Bing Tian、Yangyang Yang、Xiaojia Si、Florian F. Mulks、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/adsc.201900264
日期:2019.7.2
highly stereoselectivesynthesis of alkynyloxazolines via a gold‐catalyzed domino cyclization‐alkynylation cascade of N‐propargylcarboxamides with benziodoxole reagents is reported. This new protocol, which represents an attractive alternative to two step sequences based on Sonagashira couplings, offers a broad substrate scope, excellent functional group tolerance, and perfect stereoselectivity. A comparison
Enantioselective Catalytic Cyclopropanation–Rearrangement Approach to Chiral Spiroketals
作者:Kuioyng Dong、Raj Gurung、Xinfang Xu、Michael P. Doyle
DOI:10.1021/acs.orglett.1c01113
日期:2021.5.21
A highly enantioselective synthesis of chiral heterobicyclic spiroketals is reported via a “one-pot” cyclopropanation–rearrangement (CP-RA) cascade reaction that is sequentially catalyzed by a chiral Rh(II) catalyst and tetrabutylammonium fluoride (TBAF). Exocyclic vinyl substrates form spirocyclopropanes with tert-butyldimethylsilyl-protected enoldiazoacetates in excellent yields and with excellent
Inhibitors of HIV-1 Protease by Using In Situ Click Chemistry
作者:Matthew Whiting、John Muldoon、Ying-Chuan Lin、Steven M. Silverman、William Lindstrom、Arthur J. Olson、Hartmuth C. Kolb、M. G. Finn、K. Barry Sharpless、John H. Elder、Valery V. Fokin