We report a Pd-catalyzed halocyclization of unactivated 1,6-diynes with N-bromosuccinimide (NBS). This approach produces stereo-defined dibromo substituted dihydropyrans, tetrahydropyridines, and 3-methylene cyclohexenes with exocyclic double bond appendages in mostly good yields. Copper salt was found to be a useful Lewis acid in this reaction. Mechanistically, a formal anti-carbopalladation and a
我们报告了未活化的1,6-二炔与N-溴代琥珀酰亚胺(NBS)的Pd催化卤代环化反应。这种方法可生产立体定义明确的二溴取代的二氢吡喃,四氢吡啶和3-亚甲基环己烯,并带有环外双键附件,且收率很高。发现铜盐是该反应中有用的路易斯酸。从机理上讲,提出了一种形式上的抗碳氢键合和溴化物自由基促进的Pd II -Pd III -Pd I -Pd II催化循环,参与了二溴取代产物的形成。将二氢吡喃衍生物进一步官能化后进行B(C 6 F 5)3-催化的开环并还原得到具有优异立体选择性的二溴代1,3-二烯。
Cp*Co(III)-Catalyzed Regioselective Synthesis of Cyclopenta[<i>b</i>]carbazoles via Dual C(sp<sup>2</sup>)–H Functionalization of 1-(Pyridin-2-yl)-indoles with Diynes
作者:Qiuyun Li、Yanwei Wang、Bin Li、Baiquan Wang
DOI:10.1021/acs.orglett.8b03438
日期:2018.12.21
Cp*Co(III)-catalyzedsynthesis of cyclopenta[b]carbazoles from 1-(pyridin-2-yl)-indoles and diynes is developed. This reaction involves dual C–H activation of indoles and domino cyclizations with diynes and has excellent regioselectivity, high efficiency, a broad substrate scope, and tolerance for various functional groups. A series of cyclopenta[b]carbazole molecular scaffolds are obtained in good
开发了Cp * Co(III)催化的1-(吡啶-2-基)-吲哚和二炔合成环戊[ b ]咔唑的方法。该反应涉及吲哚的双重C–H活化和带有二炔的多米诺环化反应,具有出色的区域选择性,高效率,广泛的底物范围以及对各种官能团的耐受性。以良好或优异的产率获得了一系列环戊[ b ]咔唑分子支架。
Rh<sup>III</sup>-Catalyzed Synthesis of Cyclopenta[<i>b</i>]carbazoles via Cascade C–H/C–C Bond Cleavage and Cyclization Reactions: Using Amide as a Traceless Directing Group
作者:Yanwei Wang、Bin Li、Baiquan Wang
DOI:10.1021/acs.orglett.9b03969
日期:2020.1.3
Rhodium-catalyzed cascade C-H/C-C cleavage and cyclization reactions of 3-amide substituted indoles with diynes to construct cyclopenta[b]carbazoles have been developed. A strategy amide worked as a novel traceless directing group along with C-C bondcleavage via Friedel-Crafts-retro reaction has been disclosed in this protocol. This method exhibits a broad substrate scope and tolerates various functional
An offer you can′t re‐fused: The first examples of a convenient domino synthesis of 7,11‐diphenyl‐9,10‐dihydro‐8H‐cyclopentaphenanthridine derivatives, such as 3, by the domino palladium‐catalyzed cyclization reactions of simple 1,6‐diynes with bromo(iso)quinoline in a single operation are described.
Rhodium(I)‐Catalyzed Asymmetric Hydroarylative Cyclization of 1,6‐Diynes to Access Atropisomerically Labile Chiral Dienes
作者:Panjie Hu、Lingfei Hu、Xiao‐Xi Li、Mengxiao Pan、Gang Lu、Xingwei Li
DOI:10.1002/anie.202312923
日期:2024.1.2
Rhodium(I)-catalyzed hydroarylative cyclization of 1,6-diynes with three distinct classes of arenes has been realized, enabling highly enantioselective synthesis of a broad range of axially chiral 1,3-dienes that are conformationally labile. Detailed mechanistic studies have been explored by experimental and computational methods.