Ring-opening reaction of unactivated 3-arylaziridine-2-carboxylates with nitrile reagents

Aryldiazonium ion initiated C–N bond cleavage for the versatile, efficient and regioselective ring opening of aziridines

Aryldiazonium salts have been proved to initiate the regioselective cleavage of aziridines for the installation of varied functional groups.

2-Azaallyl Anions, 2-Azaallyl Cations, 2-Azaallyl Radicals, and Azomethine Ylides

This review covers the use of 2-azaallyl anions, 2-azaallyl cations, and 2-azaallyl radicals in organic synthesis up through June 2018. Particular attention is paid to both foundational studies and recent advances over the past decade involving semistabilized and nonstabilized 2-azaallyl anions as key intermediates in various carbon-carbon and carbon-heteroatom bond-forming processes. Both transition-metal-catalyzed and transition-metal-free transformations are covered. Azomethine ylides, which have received significant attention elsewhere, are discussed briefly with the primary focus on critical comparisons with 2-azaallyl anions in regard to generation and use.

The Ti-BINOLate-catalyzed, enantioselective ring-opening of meso-aziridines with amines

The titanium-BINOLate-catalyzed, highly enantioselective ring-opening reaction of meso-aziridines has been developed which furnishes trans-1,2-diamines in typically good yields and excellent enantioselectivities. N-Aryl aziridines attached to a 5- or 6-membered carbocyclic ring are among the best substrates for this process providing the products in up to >99% ee. The chiral catalyst is easily prepared in situ from commercially available components and does not require any laborious ligand synthesis. Structural investigations into the catalyst composition reveal an oligomeric structure of the active Ti-complex.

Lewis acid-catalyzed [3 + 2]cyclo-addition of alkynes with N-tosyl-aziridines via carbon-carbon bond cleavage: synthesis of highly substituted 3-pyrrolines

A novel, efficient, and highly regioselective Lewis acid-catalyzed [3 + 2] cycloaddition of alkynes with azomethine ylides, which are easily obtained from N-tosylaziridines via C-C bond heterolysis at room temperature was developed. Moderate enantioselectivity (70% ee) can be achieved by the application of the commercially available chiral Pybox 7 as the ligand.