Radical Cation Cyclopropanations via Chromium Photooxidative Catalysis
作者:Francisco J. Sarabia、Eric M. Ferreira
DOI:10.1021/acs.orglett.7b01095
日期:2017.6.2
The chromium photocatalyzed cyclopropanation of diazo reagents with electron-rich alkenes is described. The transformation occurs under mild conditions and features specific distinctions from traditional diazo-based cyclopropanations (e.g., avoiding β-hydride elimination, chemoselectivity considerations, etc.). The reaction appears to work most effectively using chromium catalysis, and a number of
Benign catalysis with iron: facile assembly of cyclobutanes and cyclohexenes <i>via</i> intermolecular radical cation cycloadditions
作者:Yushuang Yu、Yu Fu、Fangrui Zhong
DOI:10.1039/c8gc00299a
日期:——
We describe novel and facile iron-catalyzed crossed intermolecular radical cation cycloadditions of styrenes. This catalysis features high efficiency, atom economy, stereospecificity, scalability and very mild reaction conditions. Thus, these reactions represent a benign and sustainable strategy for the synthesis of valuable functionalized cyclobutanes and cyclohexenes.
Catalytic Intermolecular C(sp<sup>3</sup>)–H Amination: Selective Functionalization of Tertiary C–H Bonds vs Activated Benzylic C–H Bonds
作者:Erwan Brunard、Vincent Boquet、Elsa Van Elslande、Tanguy Saget、Philippe Dauban
DOI:10.1021/jacs.1c03872
日期:2021.5.5
A catalytic intermolecular amination of nonactivated tertiary C(sp3)–H bonds (BDE of 96 kcal·mol–1) is reported for substrates displaying an activated benzylic site (BDE of 85 kcal·mol–1). The tertiary C(sp3)–H bond is selectively functionalized to afford α,α,α-trisubstituted amides in high yields. This unusual site-selectivity results from the synergistic combination of Rh2(S-tfpttl)4, a rhodium(II)
Enantio- and Regioselective Ni-Catalyzed <i>para</i>-C–H Alkylation of Pyridines with Styrenes via Intermolecular Hydroarylation
作者:Jun-Bao Ma、Xia Zhao、Dongju Zhang、Shi-Liang Shi
DOI:10.1021/jacs.2c04043
日期:2022.8.3
pyridines through the use of a Ni–Al bimetallic catalyst system and N-heterocyclic carbene (NHC) ligand for intermolecular hydroarylation of styrenes. The reaction procceds in high to excellent enantioselectivities (up to 98.5:1.5 er) and high site-selectivities for both styrene and pyridine components (up to >98:2). Consequently, a broad range of enantioenriched 1,1-diarylalkanes containing pyridine