Photoredox-Enabled Synthesis of ß-Substituted Pyrroles from Pyrrolidines.

The merger of photoredox-initiated enamine-imine tautomerization and nucleophilic addition processes to access ß-substituted pyrroles from pyrrolidines has been achieved. The significant advantage of this method is suppressing the Friedel-Crafts reaction, which usually occurs between N-aryl pyrrolidines and the highly electrophilic ketoesters. The good functional group tolerance, high atom economy, and high regioselectivity as well as easy handling conditions make it an appealing alternative to synthesize ß-substituted pyrroles.

Synthesis of Tetrahydro[1,3,4]triazepines via Redox-Neutral α-C(sp3)-H Amination of Cyclic Amines.

A Brønsted acid-catalyzed α-C(sp3)-H amination of cyclic amines using hydrazines as coupling partners has been reported. This methodology provides a unique protocol to the one-step assembly of tetrahydro[1,3,4]triazepines via [1,5]-hydride transfer-initiated C(sp3)-H amination. This reaction features mild conditions, good yields, and high atom economy.

Organocatalytic Cascade ß-Functionalization/Aromatization of Pyrrolidines via Double Hydride Transfer.

An unprecedented cascade ß-functionalization/aromatization reaction of N-arylpyrrolidines was established. A series of ß-substituted arylpyrroles embedded with trifluoromethyl groups are provided directly from N-arylpyrrolidines. The deuterium-labeling experiments indicate that sequential double hydride transfer processes serve as the key steps in this transformation.

Hydride Transfer Initiated Redox-Neutral Cascade Cyclizations of Aurones: Facile Access to [6,5] Spirocycles.

Reported herein is the hydride transfer initiated redox-neutral cascade cyclizations of aurones, providing a variety of [6,5] spiro-heterocycles in satisfactory yields and good diastereoselectivities.

Redox-Neutral ß-C(sp3)-H Functionalization of Cyclic Amines via Intermolecular Hydride Transfer.

Herein, we report the first redox-neutral and transition-metal-free ß-C(sp3)-H functionalization of cyclic amines via a consecutive intermolecular hydride transfer process. A series of N-aryl pyrrolidines and N-aryl 1,2,3,4-tetrahydropyridines decorated with CF3 and carboxylic ester functionalities are directly accessed in good yields from pyrrolidines and piperidines. This work pushes forward the application of the intermolecular hydride transfer strategy in one-step assembly of molecular complexity.

Facile synthesis of magnetic homochiral metal-organic frameworks for "enantioselective fishing".

Magnetic functionalized homochiral metal-organic frameworks (MOFs) were prepared and applied to efficient enantioselective fishing of chiral drug intermediates. Under optimized conditions, the enantiomeric excess (ee) value as high as 85.2% was achieved for methyl phenyl sulfoxide (MPS) within 3 min.