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
C-H insertion. By employing chiral diphenylethylene diamine (dpen) as ligands bearing electron-withdrawing arylsulfonyl substituents, the reactions occur with remarkable chemo- and enantioselectivities; the competing Curtius-type rearrangement was largely suppressed. Enantioselective nitreneinsertion to allylic/propargylic C-H bonds was also achieved with remarkable tolerance to the C═C and C≡C bonds
作者:Son H. Doan、Mohanad A. Hussein、Thanh Vinh Nguyen
DOI:10.1039/d1cc02947a
日期:——
used to be one of the most powerful synthetic tools to functionalize alcohols and nitriles, providing valuable N-alkyl amide products. However, this reaction has not been frequently used in modern organicsynthesis due to its employment of strongly acidic and harsh reaction conditions, which often lead to complicated side reactions. Herein, we report the development of a new method using salts of the
Synthesis of Lactams via Ir-Catalyzed C–H Amidation Involving Ir-Nitrene Intermediates
作者:Jitian Liu、Wenjing Ye、Shuojin Wang、Junrong Zheng、Weiping Tang、Xiaoxun Li
DOI:10.1021/acs.joc.0c00157
日期:2020.3.20
We have developed a divergent strategy for the synthesis of five- and six-membered lactams via either an amidation of sp3 C-H bonds or electrophilic substitution of arenes via Ir-nitrene intermediates. With the employment of a readily available iridium catalyst in dichloromethane or hexafluoro-2-propanol, a wide range of lactams were synthesized in good to excellent yields with high selectivity.