Introducing Axial Chirality into Mesoionic 4,4鈥?Bis(1,2,3-triazole) Dicarbenes
文摘
Mesoionic 4,4鈥?bis(1,2,3-triazole-5,5鈥?diylidene) Rh(I) complexes having a C2 chiral 4,4鈥?axis were accessed from 3-alkyltriazolium salts in virtually complete de. Their structure and configurational integrity were assessed by NMR spectroscopy, X-ray crystallography, and chiral HPLC. Computational analysis of the MICs involved in the reaction suggested the formation of a highly stable and unprecedented cation-carbene intermediate species, which could be evidenced experimentally by cyclic voltammetry analysis.