Rhodium-catalyzed ortho-selective C–H halogenation of 2-arylbenzo[d]thiazoles using N-halosuccinimides as halogen sources
摘要:
A series Rh(III)-catalyzed ortho-selective C-H halogenation of 2-arylbenzo[d]thiazoles has been developed using N-halosuccinimides (NXS, X=Br and I) as halogen sources. ortho-Brominated and iodinated various 2-arylbenzo[d]thiazoles could be accessed in good to excellent yields and high regioselectivity under mild reaction conditions. (C) 2015 Elsevier Ltd. All rights reserved.
Efficient 2-aryl benzothiazole formation from acetophenones, anilines, and elemental sulfur by iodine-catalyzed oxidative C(CO)-C(alkyl) bond cleavage
摘要:
A novel and efficient iodine-catalyzed one-pot reaction of aromatic amines, acetophenones, and elemental sulfur for the synthesis of 2-aryl benzothiazoles is described. The process involves sequential C-S and C-N bond formation followed by C(CO)-C bond cleavage from readily accessible starting materials. A wide range of functional groups is tolerated under oxidant and metal-free condition and moderate to good product yields are obtained. (C) 2018 Elsevier Ltd. All rights reserved.
An efficient synthetic route to biologically relevant 2-phenylbenzothiazoles substituted on the benzothiazole ring
作者:Ashley A. Weekes、Mark C. Bagley、Andrew D. Westwell
DOI:10.1016/j.tet.2011.08.004
日期:2011.10
focus on their unsubstituted ring counterparts. Here we describe a new concise and efficient synthetic route to biologically relevant 2-phenylbenzothiazoles in high yield from the reaction of substituted 2-aminothiophenol disulfides and benzaldehydes, promoted by the inexpensive and non-toxic inorganic oxidant sodiummetabisulfite in DMSO at 120 °C. Our new method is tolerant of a range of substituents
A mild and efficient substrate-assisted CHbond cyanation of 2-arylbenzothiazoles has been developed using CuCN as cyano-group source. The reaction exhibits broad functional groups tolerance giving the desired products in moderate to excellent yields. Regioselective cyanation was in favor of the less sterically hindered position to those meta-substituted substrate.
An efficient palladium-catalysed protocol for direct C–H bond acylation by cross coupling of 2-arylbenzo[d]thiazoles and aldehydes using tert-butyl hydroperoxide as the oxidant is reported. The process provides a useful method for the synthesis of aromatic ketones directly from aldehydes. In addition, the reaction can tolerate various functional groups in good yield with high regioselectivity.
Pd(PPh3)4-catalyzed direct ortho-fluorination of 2-arylbenzothiazoles with an electrophilic fluoride N-fluorobenzenesulfonimide (NFSI)
作者:Qiuping Ding、Changqing Ye、Shouzhi Pu、Banpeng Cao
DOI:10.1016/j.tet.2013.11.034
日期:2014.1
An efficient protocol was developed for regio-selective Pd-catalyzed direct ortho-fluorination of 2-alylbenzo[d]thiazoles using N-fluorobenzenesulfonimide (NFSI) as the F+ source, and L-proline as the crucial promoter. The present method offered a practical route to synthesize valuable fluorinated products, which are of potential importance in the pharmaceutical and agrochemical industries. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.
Palladium-catalyzed direct ortho-acylation through an oxidative coupling of 2-arylbenzothiazoles with benzylic alcohols
An efficient protocol was developed for Pd-catalyzed direct C H bond acylation by cross-dehydrogenative-coupling of arylbenzothiazoles and benzylic alcohols using tert-butyl hydroperoxide (TBHP) as the oxidant. The acylation reactions exhibit good reactivities and excellent regioselectivity. (C) 2013 Elsevier Ltd. All rights reserved.