A regioselectivity switch in Pd-catalyzed hydroallylation of alkynes
作者:Ding-Wei Ji、Yan-Cheng Hu、Hao Zheng、Chao-Yang Zhao、Qing-An Chen、Vy M. Dong
DOI:10.1039/c9sc01527b
日期:——
Through rational evaluation of ligands and promoters, the reactivity of a key Pd(ii) species towards transmetalation or β-H elimination is manipulated.
通过对配体和促进剂的理性评估,可以操控关键的Pd(II)物种对于金属转移或β-H消除的活性。
Radical-mediated vicinal addition of alkoxysulfonyl/fluorosulfonyl and trifluoromethyl groups to aryl alkyl alkynes
of sulfonyl radicals to alkenes and alkynes is a valuable method for constructing useful highly functionalized sulfonyl compounds. The underexplored alkoxy- and fluorosulfonyl radicals are easily accessed by CF3 radical addition to readily available allylsulfonic acid derivatives and then β-fragmentation. These substituted sulfonyl radicals add to aryl alkyl alkynes to give vinyl radicals that are trapped
The present invention provides heterogeneous organometallic catalysts for alkyne metathesis, including the metathesis of internal alkynes. Organometallic precursors are covalently bonded to the oxygen atoms of metal oxide supports to form catalysts having carbyne functionality. The heterogeneous catalysts provide improved turn-over frequencies at lower reaction temperatures than conventional catalysts.
Three-Component Friedel–Crafts Transformations: Synthesis of Alkyl and Alkenyl Trifluoromethyl Sulfides and Alkenyl Iodides
作者:Duc Chu、Jonathan A. Ellman
DOI:10.1021/acs.orglett.2c00924
日期:2022.4.22
and alkyl trifluoromethyl sulfides from arenes, (PhSO2)2NSCF3, and alkynes or alkenes, respectively. The transformations proceed with high regio- and stereochemical control via the initial formation of cationic thiirenium and thiiranium intermediates, respectively, followed by Friedel–Crafts reactions with the arene. A mechanistically related three-component synthesis of alkenyl iodides from arenes
A novel regio- and stereoselective reductive coupling of vinyl azaarenes and alkynes has been developed to access functionalized azaarene compounds bearing stereodefined tri-substituted alkenes via photoredox cobalt dualcatalysis. Simple organic base together with alcohol has been applied as the hydrogen sources instead of commonly used Hantzsch esters in this coupling reaction.