Use of Strain-Release for the Diastereoselective Construction of Quaternary Carbon Centers
作者:Tobias Pinkert、Mowpriya Das、Malte L. Schrader、Frank Glorius
DOI:10.1021/jacs.1c03492
日期:2021.5.26
formation of quaternary carbon centers with excellent diastereoselectivity via a strain-release protocol. An organometallic species is generated by Cp*Rh(III)-catalyzed C–H activation, which is then coupled with strained bicyclobutanes (BCBs) and a prochiral carbon electrophile in a three-component reaction. This work illustrates a rare example of BCBs in transition metal catalysis and demonstrates their
A palladium-catalyzed ortho-directed alkylation of O-methyl ketoximes that proceeds through a regioselective ring-opening reaction of epoxides has been demonstrated. This C(sp2)–H activation/alkylation protocol was carried out in pivalic acid/1,1,1,3,3,3-hexafluoro-2-propanol (PivOH/HFIP, 2:8) as the solvent and was applied to various O-methyl ketoximes that contain either electron-donating or electron-withdrawing
Rh(III)-Catalyzed C–H Alkylation of Arenes Using Alkylboron Reagents
作者:He Wang、Songjie Yu、Zisong Qi、Xingwei Li
DOI:10.1021/acs.orglett.5b01232
日期:2015.6.5
alkylation of arenes using commercially available alkyltrifluoroborates is disclosed. Oximes, heteroarenes, azomethines, N-nitrosoamines, and amides are viable directing groups to entail this transformation. The alkyl group in the boron reagent can be extended to primary alkyls, benzyl, and cycloalkyls, and the reaction proceeded with controllable mono- and dialkylation selectivity when both ortho C–H
Diaryliodoniums by Rhodium(III)-Catalyzed CH Activation: Mild Synthesis and Diversified Functionalizations
作者:Fang Xie、Zhipeng Zhang、Xinzhang Yu、Guodong Tang、Xingwei Li
DOI:10.1002/anie.201502278
日期:2015.6.15
Diaryliodonium salts play an increasingly important role as an aryl source. Reported is the first synthesis of diaryliodoniums by rhodium(III)‐catalyzed CH hyperiodination of electron‐poor arenes under chelation assistance. This CI coupling reaction occurred at room temperature with high regio‐selectivity and functional‐group compatibility. Subsequent diversified nucleophilic functionalization of
Ruthenium(II)-Catalyzed α-Fluoroalkenylation of Oxime Ethers with <i>gem</i>-Difluorostyrenes <i>via</i> C–H Activation and C–F Cleavage
作者:Lili Zhang、Kezuan Deng、Gaorong Wu、Jinyue Yang、Shibiao Tang、Xiaopan Fu、Chengcai Xia、Yafei Ji
DOI:10.1021/acs.joc.0c01842
日期:2020.10.2
A novel route for ruthenium(II)-catalyzed α-fluoroalkenylation of oxime ethers with gem-difluorostyrenes via C–Hactivation and C–F cleavage has been developed for the first time. Notably, the alkenyl units of products exhibit exclusive Z-configuration. This reaction features a broad substrate scope and good functional group tolerance. A plausible reaction mechanism is confirmed by an available cycloruthenated