Controllable Skeletal and Peripheral Editing of Pyrroles with Vinylcarbenes

The skeletal editing of azaarenes through insertion, deletion, or swapping of single atoms has recently gained considerable momentum in chemical synthesis. Here, we describe a practical skeletal editing strategy using vinylcarbenes in situ generated from trifluoromethyl vinyl N-triftosylhydrazones, leading to the first dearomative skeletal editing of pyrroles through carbon-atom insertion. Furthermore, depending on the used catalyst and substrate, three types of peripheral editing reactions of pyrroles are also disclosed: α- or γ-selective C-H insertion, and [3+2] cycloaddition. These controllable molecular editing reactions provide a powerful platform for accessing medicinally relevant CF3-containing N-heterocyclic frameworks, such as 2,5-dihydropyridines, piperidines, azabicyclo[3.3.0]octadienes, and allylated pyrroles from readily available pyrroles. Mechanistic insights from experiments and density functional theory (DFT) calculations shed light on the origin of substrate- or catalyst-controlled chemo- and regioselectivity as well as the reaction mechanism.

Nickel-catalyzed mild synthesis of functional γ-amino butyric acid esters via direct α-C(sp3)-H allylation of N-alkyl anilines with allyl sulfones

Herein, by employing a readily available Ni(OAc)2·4H2O/TBHP catalyst system, we present a new method for mild synthesis of α-methylene-γ-amino butyric acid esters via direct α-C(sp3)-H allylation of N-alkyl anilines with allyl sulfones under oxidative nickel catalysis. The synthetic protocol proceeds with good substrate and functional group compatibility, operational simplicity, the use of base metal catalysts and easily accessible feedstocks, and no need for pre-functionalization of the α-site of N-alkyl anilines. In addition, the obtained products are applicable for further elaboration of functional molecules.

Ruthenium/acid co-catalyzed reductive α-phosphinoylation of 1,8-naphthyridines with diarylphosphine oxides

By an in situ coupling-interrupted transfer hydrogenation strategy, a direct construction of novel α-phosphinoyl 1,2,3,4-tetrahydronaphthyridines via ruthenium/acid co-catalyzed reductive α-phosphinoylation of 1,8-naphthyridines with diarylphosphine oxides is demonstrated.

Progress and prospects in copper-catalyzed C-H functionalization

Copper-catalyzed C-H functionalization is becoming a significant area in organic chemistry. Copper is now widely used as a catalyst in organic synthesis as it is inexpensive and not very toxic. Functionalization of C-H bonds to construct wide varieties of organic compounds has received much attention in recent times. This review focuses on the recent advances in Cu-catalyzed C-H functionalization and covers literature from 2018-2020.