Cu-Catalyzed Tandem Aerobic Oxidative Cyclization for the Synthesis of 3,3′-Bipyrroles from the Homopropargylic Amines
作者:Zhenjie Qi、Yong Jiang、Bingxiang Yuan、Yanning Niu、Rulong Yan
DOI:10.1021/acs.orglett.8b02201
日期:2018.8.17
Cu-catalyzed method for the synthesis of 3,3′-bipyrroles from homopropargylic amines through tandem aerobic oxidative cyclization involving the formation of C–C bond has been developed. The features of this reaction are a small number of Cu catalysis and simple starting substrates. Moreover, this procedure exhibits good functional group tolerance and a series of 3,3′-bipyrroles derivatives are obtained
External Oxidant‐Free Oxidative Tandem Cyclization: NaI‐Catalyzed Thiolation for the Synthesis of 3‐Thiosubstituted Pyrroles
作者:Bingxiang Yuan、Yong Jiang、Zhenjie Qi、Xin Guan、Ting Wang、Rulong Yan
DOI:10.1002/adsc.201900620
日期:2019.11.19
A simple method for the synthesis of 3‐thiosubstituted pyrroles from homopropargylic amines and thiosulfonates via a tandem sulfenylation/cyclization has been developed. The thiosulfonates are used both as substrates and oxidants in this transformation. This procedure exhibits good functional group tolerance and a series of 3‐thiosubstituted pyrrole derivatives are obtained in moderate to good yields
Cascade Reaction of Alkynols and 7-Oxabenzonorbornadienes Involving Transient Hemiketal Group Directed C–H Activation and Synergistic Rh<sup>III</sup>/Sc<sup>III</sup> Catalysis
作者:Deng Yuan Li、Liang Liang Jiang、Shuang Chen、Zheng Lu Huang、Li Dang、Xin Yan Wu、Pei Nian Liu
DOI:10.1021/acs.orglett.6b02587
日期:2016.10.7
As the first cascade C–Hactivationdirected by a transient group, reaction of alkynols and 7-oxabenzonorbornadienes has been achieved via synergistic rhodium and scandium catalysis to afford spirocyclic dihydrobenzo[a]fluorenefurans. This transformation proceeds by a transient hemiketal group directedC–Hactivation, dehydrative naphthylation, and intramolecular Prins-type cyclization. Mechanistic
作为由一个瞬态基团控制的第一个级联C–H活化,炔醇与7-氧杂苯并降冰片二烯的反应已通过协同的铑和scan催化作用而得到,以提供螺环二氢苯并[ a ]芴呋喃。这种转化是通过一个半胱氨酸基团直接引导C–H活化,脱水萘化和分子内Prins型环化而进行的。机理研究和密度泛函理论计算表明,决定速率的步骤是C–H键断裂,瞬态半酮基和协同Rh III / Sc III催化均起关键作用。
A Sequential Activation of Alkyne and C–H Bonds for the Tandem Cyclization and Annulation of Alkynols and Maleimides through Cooperative Sc(III) and Cp*-Free Co(II) Catalysis
[4 + 2] oxidative Diels–Alder reaction of readily available alkynols with maleimide is achieved for the rapid access of pthalimide-fused multicyclic compounds. The reaction is proposed to go through a sequence of Sc(OTf)3-catalyzed electrophilic cyclization, ligand exchange with Cp*-free cobalt, and C–H activation followed by maleimide insertion.
An intramolecular Friedel–Crafts reaction of N-methoxymethyl sulfoneamides 3e–j containing an acetylene dicobalt moiety was found to proceed smoothly to afford eight- and nine-membered cyclic amines 4e–j in high yields.