10.1039/b922166b
The research focuses on the synthesis and application of azaphosphiridine complexes, specifically exploring novel access to these complexes and their first applications in Br?nsted acid-induced ring expansion reactions. The study utilizes reactants such as 2H-azaphosphirene complex 1, N-methyl C-aryl imines 2a-e, and transient Li/Cl phosphinidenoid complex 5, which are subjected to thermal group transfer reactions or reactions with dichloro(organo)phosphane complex 4. The experiments involve the synthesis of azaphosphiridine complexes 3a-e and their subsequent reactions with trifluoromethane sulfonic acid and dimethyl cyanamide, leading to the formation of 1,3,4-diazaphosphol-2-ene complexes 8a,d. The analysis of the products and intermediates is conducted using a variety of techniques including multinuclear NMR spectroscopy, IR and UV/Vis spectroscopy, mass spectrometry (MS), and single-crystal X-ray crystallography for complexes 3b-d, 8a, and 8d. Additionally, DFT studies are presented to provide insights into the reaction mechanisms and compliance constants of the model complex of 6a.