Green and Rapid Access to Benzocoumarins<i>via</i>Direct Benzene Construction through Base-Mediated Formal [4+2] Reaction and Air Oxidation
作者:Chengli Mou、Tingshun Zhu、Pengcheng Zheng、Song Yang、Bao-An Song、Yonggui Robin Chi
DOI:10.1002/adsc.201500771
日期:2016.3.3
typically with an intramolecular ester forming reaction to make the lactone ring as the last step. Another major method involves transition metal‐catalyzed coupling or carbon‐hydrogen bond activation reactions starting with pre‐existing aryl frameworks in the substrates. Here we report a new strategy for the green and rapidaccess to benzocoumarins and their derivatives. Our method uses readily available
Palladium-Catalyzed Site-Selective Benzocylization of Aromatic Acids with <i>o</i>-Fluoro-Substituted Diaryliodonium Salts toward 3,4-Benzocoumarins
作者:Cheng Pan、Limin Wang、Jianwei Han
DOI:10.1021/acs.orglett.0c01577
日期:2020.6.19
By using 2-fluoro-substituted diaryliodoniumsalts, a novel benzocylization has been accomplished for the synthesis of 3,4-benzocoumarin derivatives via a cascade of ortho-arylation and defluorination in the presence of palladium catalysts. The reaction exhibits a broad compatibility of readily available aromatic acids with an excellent level of site-selectivity. Mechanistic investigations revealed
Syntheses of functionalized benzocoumarins by photoredox catalysis
作者:Qihong Lai、Shanyi Chen、Linnan Zou、Chengzhi Lin、Shuling Huang、Lailing Fu、Lina Cai、Shunyou Cai
DOI:10.1039/d2ob02225g
日期:——
We report a new method for the synthesis of functionalized benzocoumarins through the strategy of activation of multiple C–H bonds on 2-aryl toluenes under visible-light-enabled photoredox conditions.
δ-Acetoxy Allenoate as a <i>5C</i>-Synthon in Domino-Annulation with Sulfamidate Imines: Ready Access to Coumarins
作者:Sachin Chauhan、A. Sanjeeva Kumar、K. C. Kumara Swamy
DOI:10.1021/acs.joc.3c01183
日期:2023.9.1
A DMAP-catalyzed sequential benzannulation and lactonization strategy in which δ-acetoxy allenoate functions as a 5C-synthon in its reaction with cyclic sulfamidate imines is reported. This platform delivers π-extended coumarin frameworks under metal-free conditions via allylic elimination followed by Mannich coupling, proton shifts, C–N bond cleavage, and lactonization as key steps. The driving force