Cascade reactions are an important strategy in reaction design, allowing streamlining of chemical synthesis. Here we report a cascade Suzuki–Miyaura/Diels–Alder reaction, employing vinyl Bpin as a bifunctional reagent in two distinct roles: as an organoboron nucleophile for cross-coupling and as a Diels–Alder dienophile. Merging these two reactionsenables a rapid and operationally simple synthesis
Rhodium(III)-Catalyzed Cyclopropanation of Unactivated Olefins Initiated by C–H Activation
作者:Erik J. T. Phipps、Tiffany Piou、Tomislav Rovis
DOI:10.1055/s-0039-1690130
日期:2019.9
We have developed a Rh(III)-catalyzed cyclopropanation of unactivated olefins initiated by an alkenyl C-H activation. A variety of 1,1-disubstituted olefins undergo efficient cyclopropanation with a slight excess of alkene stoichiometry. A series of mechanistic interrogations implicate a metal-carbene as an intermediate.
Copper(I) iodide-catalyzed oxidative C(sp2)–H functionalization of pyridines and isoquinolines for the synthesis of imidazo[1,2-a]pyridines and 2-phenylimidazo[2,1-a]isoquinolines with vinyl azides under mild aerobic conditions is reported. Good selectivity for 3-substitutedpyridines and single isomer formation with isoquinolines were observed.
碘化铜(I)催化吡啶和异喹啉的碘化铜(I 2)催化氧化C(sp 2)–H官能团,用于在温和的条件下用乙烯基叠氮化物合成咪唑并[1,2- a ]吡啶和2-苯基咪唑并[ 2,1- a ]异喹啉有氧条件的报道。观察到对3-取代的吡啶具有良好的选择性,并与异喹啉形成了单一异构体。
Facile NBS/DMSO mediated dibromination of olefins including selected natural products and glycals
作者:Hafiz Ul Lah、Shabir Ahmad Mir、Gulzar Hussain、Rafiq Ahmad Wani、Syed Khalid Yousuf
DOI:10.1007/s12039-021-02003-3
日期:2022.3
diastereoselective vic-dibromination of olefins has been developed. The process employs a readily available N-Bromosuccinimide (NBS)/DMSO reagent system as a bromine source. High substrate scope, simple reaction conditions, application to natural products and glycals makes the process very attractive. Graphical abstract A highly chemo- and diastereoselective vic-dibromination of olefins has been developed. The process
Rh(III)-Catalyzed C–H Activation-Initiated Directed Cyclopropanation of Allylic Alcohols
作者:Erik J. T. Phipps、Tomislav Rovis
DOI:10.1021/jacs.9b02156
日期:2019.5.1
annulation onto allylic alcohols initiated by alkenyl C-H activation of N-enoxyphthalimides to furnish substituted cyclopropyl-ketones. Notably, the traceless oxyphthalimide handle serves three functions: directing C-H activation, oxidation of Rh(III), and, collectively with the allylic alcohol, in directing cyclopropanation to control diastereoselectivity. Allylic alcohols are shown to be highly reactive