Arylation of Terminal Alkynes: Transition-Metal-Free Sonogashira-Type Coupling for the Construction of C(sp)–C(sp<sup>2</sup>) Bonds
作者:Mingxing Ye、Mengyuan Hou、Yahao Wang、Xingxing Ma、Kai Yang、Qiuling Song
DOI:10.1021/acs.orglett.3c00586
日期:2023.3.17
Sonogashira reactions, a transition-metal-free version of the arylation of terminal alkynes is elusive. Herein, we report an efficient transition-metal-free Sonogashira-typecoupling reaction for the one-pot arylation of alkynes to construct C(sp)–C(sp2) bonds from a tetracoordinate boron intermediate with NIS as a mediator. With its high efficiency, wide substrate range, and good functional group tolerance
Modular assembly of versatile tetrasubstituted alkenyl monohalides from alkynyl tetracoordinate borons
作者:Xingxing Ma、Luo Li、Mengwei Tan、Zihao Zhong、Jinchao Liang、Puhui Li、Qiuling Song
DOI:10.1016/j.chempr.2023.01.005
日期:2023.2
assembly of fully carbon tetrasubstituted olefins, the synthesis of tetrasubstituted alkenyl monohalides are underdeveloped and elusive. Herein, we report four intriguing migration reactions from alkynyl tetracoordinate boron species, in which various common, inexpensive, and user-friendly halogen electrophiles (Selectfluoro, TCCA, NIS, and NBS) are suitable electrophilic halogen sources. Versatile
Iodination–Group-Transfer Reactions to Generate Trisubstituted Iodoalkenes with Regio- and Stereochemical Control
作者:Joseph A. Kaplan、Suzanne A. Blum
DOI:10.1021/acs.joc.3c01495
日期:2023.9.15
amines), yielding trisubstituted acyclic alkenes and an example acyclic tetrasubstituted alkene. X-ray crystallographic determination of reaction intermediates and products confirms that the initial electrophilic-cyclization step sets the stereo- and regiochemistry of the product. The products serve as synthetic building blocks by readily participating in downstream functionalization reactions, including
三取代烯烃的区域和立体合成仍然是一个重大的合成挑战。在此,开发了一种通过从碘化亲电环化机制中转移中间体来生产区域和立体定义的三取代碘烯烃的方法。具体来说,环化锍离子对中间体通过亲核碘化物开环转化为烯烃。或者,AgOTf 清除碘化物可防止开环,从而能够分离锍离子对中间体。离子对的分离能够获得互补的反应性,包括通过替代亲核体(即胺)开环,产生三取代的无环烯烃和示例无环四取代的烯烃。反应中间体和产物的 X 射线晶体学测定证实,最初的亲电环化步骤决定了产物的立体化学和区域化学。该产品可作为合成构件,轻松参与下游官能化反应,包括氧化、钯催化交叉偶联和亲核置换。
CN116354995
申请人:——
公开号:——
公开(公告)日:——
Repurposing π Electrophilic Cyclization/Dealkylation for Group Transfer
作者:Joseph A. Kaplan、Adena Issaian、Martin Stang、David Gorial、Suzanne A. Blum
DOI:10.1002/anie.202112351
日期:2021.12
Hijacking electrophiliccyclization intermediates allows for a pathway to acyclic tri- and tetrasubstituted alkenes with predictable regio- and stereochemistry. Mechanistic studies indicate concerted thioboration of the alkyne precedes rate-determining ring opening and investigate the effects of ring-size and functional groups on reaction selectivity.