Straightforward synthesis of benzoxazoles and benzothiazoles via photocatalytic radical cyclization of 2-substituted anilines with aldehydes
作者:Hao Anh Nguyen Le、Long Hoang Nguyen、Quynh Nhu Ba Nguyen、Hai Truong Nguyen、Khang Quoc Nguyen、Phuong Hoang Tran
DOI:10.1016/j.catcom.2020.106120
日期:2020.10
Eosin Y-catalyzed one-pot coupling and cyclization of o-substituted anilines with aldehydes to form benzoxazoles and benzothiazoles under mild condition has been developed. The reaction scope was broadly tolerant of various 2-substituted anilines and aldehydes. The desired products were obtained in high yields with the use of eosin Y as a photocatalyst under a substantial refinement of reaction conditions
Palladium-catalyzed desulfitative arylation of azoles with arylsulfonyl hydrazides
作者:Xinzhang Yu、Xingwei Li、Boshun Wan
DOI:10.1039/c2ob26270c
日期:——
Palladium-catalyzed desulfitative and denitrogenative arylation of azoles with arylsulfonylhydrazides has been achieved. A broad scope of azoles and arylsulfonylhydrazides has been used to produce arylated azoles in high yields.
A palladium-catalyzed direct desulfitative C-arylation of a benzo[d]oxazole C-H bond with arene sulfonylchlorides is described. The procedure tolerates halo, cyano, nitro, trifluoromethyl, acetyl and acetylamino groups on the phenyl ring of sulfonylchlorides, providing the arylation products in moderate to good yields. It represents a practical and attractive alternative for the synthesis of 2-aryl
Direct Oxidative C–H Arylation of Benzoxazoles with Arylsulfonyl Hydrazides Promoted by Palladium Complexes
作者:Fuk Kwong、On Yuen、Chau So、Wing Wong
DOI:10.1055/s-0032-1317350
日期:——
This study describes a direct oxidative C-2 arylation of benzoxazoles using arylsulfonylhydrazides as the aryl sources. A simple catalyst system [Pd(OAc)2 and Ph3P] allows the reactions to proceed smoothly under oxidative reaction conditions. Other heteroarenes such as caffeine and benzothiazole are also applicable substrates. Notably, this catalytic system tolerates halogen substituents which provides
Deep eutectic solvent-catalyzed arylation of benzoxazoles with aromatic aldehydes
作者:Phuong Hoang Tran、Anh-Hung Thi Hang
DOI:10.1039/c8ra01094c
日期:——
A novel and efficient methodology for the arylation of benzoxazoles with aromaticaldehydes catalyzed by deep eutectic solvent has been developed. The reaction smoothly proceeded with a wide range of substrates to give the desired products in high yields within short reaction time. Deep eutectic solvents are easily recovered and reused without significant loss of catalytic activity.