α-Diazo-β-ketonitriles: Uniquely Reactive Substrates for Arene and Alkene Cyclopropanation
摘要:
An investigation of the intramolecular cyclopropanation reactions of alpha-diazo-beta-ketonitriles is reported. These studies reveal that alpha-diazo-beta-ketonitriles exhibit unique reactivity in their ability to undergo arene cyclopropanation reactions; other similar acceptor acceptor-substituted diazo substrates instead produce mixtures of C-H insertion and dimerization products. alpha-Diazo-beta-ketonitriles also undergo highly efficient intramolecular cyclopropanation of tri- and tetrasubstituted alkenes. In addition, the alpha-cyano-alpha-ketocyclopropane products are demonstrated to serve as substrates for S(N)2, S(N)2', and aldehyde cycloaddition reactions.
Radical-Mediated Strategies for the Functionalization of Alkenes with Diazo Compounds
作者:Yong-Liang Su、Geng-Xin Liu、Jun-Wen Liu、Linh Tram、Huang Qiu、Michael P. Doyle
DOI:10.1021/jacs.0c05183
日期:2020.8.12
reported. Here we report a novel reaction of diazo compounds utilizing a radical-mediated addition strategy to achieve difunctionalization of diverse alkenes. Diazo compounds are transformed to carbon radicals with a photocatalyst or an iron catalyst through PCET processes. The carbon radical selectively adds to diverse alkenes delivering new carbon radical species, then forms products through hydroalkylation
Replacing Conventional Carbon Nucleophiles with Electrophiles: Nickel-Catalyzed Reductive Alkylation of Aryl Bromides and Chlorides
作者:Daniel A. Everson、Brittany A. Jones、Daniel J. Weix
DOI:10.1021/ja301769r
日期:2012.4.11
general method is presented for the synthesis of alkylated arenes by the chemoselective combination of two electrophilic carbons. Under the optimized conditions, a variety of aryl and vinyl bromides are reductively coupled with alkyl bromides in high yields. Under similar conditions, activated aryl chlorides can also be coupled with bromoalkanes. The protocols are highly functional-group tolerant (−OH,
Nickel-Catalyzed Cross-Electrophile Coupling of Aryl Chlorides with Primary Alkyl Chlorides
作者:Seoyoung Kim、Matthew J. Goldfogel、Michael M. Gilbert、Daniel J. Weix
DOI:10.1021/jacs.0c02673
日期:2020.6.3
Alkyl chlorides and aryl chlorides are among the most abundant and stable carbon electrophiles. Although their coupling with carbon nucleophiles is well developed, the cross-electrophile coupling of aryl chlorides with alkyl chlorides has remained a challenge. We report here the first general approach to this transformation. The key to produc-tive, selective cross-coupling is the use of a small amount
作者:Pannan Miao、Ruining Li、Xianfeng Lin、Liangming Rao、Zhankui Sun
DOI:10.1039/d1gc00091h
日期:——
Cascade reactions are green and powerful transformations for building multiple carbon–carbon bonds in one step. Through a relay olefination and radical addition process, we were able to develop the cascade Wittig/hydroalkylation reactions induced by visible light. This metal-free radical approach features mild conditions, robustness, and excellent functionality compatibility. It allows access to saturated