Direct α-Chalcogenation of Aliphatic Carboxylic Acid Equivalents
作者:Aniket Gupta、Ajijur Rahaman、Sukalyan Bhadra
DOI:10.1021/acs.orglett.9b02424
日期:2019.8.2
A novel approach to α-chalcogenation of aliphaticcarboxylicacids has been developed by means of transforming them as the corresponding benzazoles. The catalyst system, consisting of CuI, DMSO, and a base, operates through a unique mechanism to access a range of practically significant thio- and selenoethers that are otherwise challenging to achieve. The applicative potentials have been exemplified
通过将脂肪族羧酸转化为相应的苯唑类,开发了一种将脂肪族羧酸进行 α-硫属元素化的新方法。由 Cu I 、DMSO 和碱组成的催化剂体系通过独特的机制运行,以获取一系列具有实际意义的硫醚和硒醚,否则这些化合物难以实现。应用潜力已通过利用所得硫属化合物作为合成生物学相关分子和合成中间体的前体来举例说明。
Catalytic Direct α-Amination of Arylacetic Acid Synthons with Anilines
A unique α-amination approach using various anilines has been developed for arylacetic acids via adaptation as benzazoles. The reaction proceeds through a single electron transfer mechanism utilizing an iron-based catalyst system to access α-(N-arylamino)acetic acid equivalents. Modification of approved drugs, facile cleavage of the benzazole auxiliary, and tolerance of amide linkage forming conditions
Pd<sup>II</sup>-Catalyzed methoxylation of C(sp<sup>3</sup>)–H bonds adjacent to benzoxazoles and benzothiazoles
作者:Jogendra Kumar、Aniket Gupta、Sukalyan Bhadra
DOI:10.1039/c9ob00337a
日期:——
The Pd(OAc)2/PhI(OAc)2 catalyst system promotes the highly regioselective dehydrogenative methoxylation of a C(sp3)–H bond adjacent to benzoxazole and benzothiazole rings. The title transformation constitutes the first example of a Pd-catalyzed C(sp3)–H activating methoxylation at the proximal-selective α-position with regard to a directing auxiliary and provides expedient access to an important class
An elegant and catalytic procedure for the one-step cyanomethylenation of C(sp3)–H bonds adjacent to benzazoles and ketones is described herein using DMF as a C-1 unit and TMSCN as the cyanide source. The copper-mediated reaction between DMF and TMSCN gives a cyanomethylene radical intermediate that reacts with 2-alkylbenzazoles or alkylketones to furnish desired cyanomethylenated compounds under palladium
A photoinduced copper-catalyzed enantioconvergent remote alkynylation of N-hydroxyphthalimide esters with terminal alkynes via 1,4-heteroaryl migration has been developed. A broad scope of heteroaryl-tethered chiral alkynes has been synthesized with good regio- and enantioselectivities. The chiral-ligand-coordinated copper species plays a dual role as both the photoredox and cross-coupling catalyst