Pd-Catalyzed Site-Selectivep-Hydroxyphenyloxylation of Benzylic α-C(sp3)–H Bonds with 1,4-Benzoquinone
摘要:
A Pd-catalyzed, site-selective p-hydroxypheny-loxylation of benzylic alpha-C(sp(3))-H bonds with 1,4-benzoquinone using thioamide as a directing group is reported. 1,4-Benzoquinone is employed as the p-hydroxyphenyloxy source without extra oxidants. This method exclusively gives site selectivity at alpha-C(sp(3))-H bonds rather than the usual beta-C(sp(3))-H bonds through C-H activation mode. The reactions proceed with high functional group tolerance in yields of 42-93%.
A palladium-catalyzed N-acylation of tertiary amines by carboxylic acids was achieved through C–N cleavage. This reaction showed a wide substrate scope. Both aromatic and aliphatic acids served well as the acylating reagents and coupled with tertiary amines to produce the corresponding amides in good to excellent yields. With the strategy, bioactive carboxylic acids were also efficiently modified,
Chemoselective formal β-functionalization of substituted aliphatic amides enabled by a facile stereoselective oxidation event
作者:Adriano Bauer、Nuno Maulide
DOI:10.1039/c9sc03715b
日期:——
Aliphatic C-H functionalization is a topic of current intense interest in organic synthesis. Herein, we report that a facile and stereoselective dehydrogenation event enables the functionalization of aliphaticamides at different positions in a one-pot fashion. Derivatives of relevant pharmaceuticals were formally functionalized in the β-position in late-stage manner. A single-step synthesis of incrustoporine
The challenging transamidation of unactivated tertiary amides using equivalent amounts of amines has been accomplished via cooperative acid/iodide catalysis. The method provides a novel manifold to re-route the reactivity of unactivated and unreactive N,N-dialkyl amides through reactive acyl iodide intermediates, representing a powerful new activation mode of unactivated amide bonds.
Photoinduced C(sp<sup>3</sup>)–H Chalcogenation of Amide Derivatives and Ethers via Ligand-to-Metal Charge-Transfer
作者:Ben Niu、Krishnakumar Sachidanandan、Maria Victoria Cooke、Taylor E. Casey、Sébastien Laulhé
DOI:10.1021/acs.orglett.2c01505
日期:2022.7.1
A photoinduced, iron(III) chloride-catalyzed C–H activation of N-methyl amides and ethers leads to the formation of C–S and C–Se bonds via a ligand-to-metal charge transfer (LMCT) process. This methodology converts secondary and tertiary amides, sulfonamides, and carbamates into the corresponding amido-N,S-acetal derivatives in good yields. Mechanistic work revealed that this transformation proceeds