Examination of Dianionic Diamide Ligand Structural Effects on Ti-Catalyzed Hydrohydrazination of Terminal Alkynes.

ABSTRACT: Ti-catalyzed alkyne hydrohydrazination of terminal alkynes using 1,1-disubstituted hydrazines is reported. Here, a variety of bi- or tridentate dianionic diamide or diamidoamine ligated Ti=NNPh₂ catalysts were examined, wherein fast and selective Ti=NNPh₂ catalysts have ligands with a "goldilocks" intermediate level of steric environment. Ti=NNPh₂ catalysts with ligands of high/medium steric bulk showed slower reactivity compared to the optimal catalysts. Catalysis with Ti complexes with sterically less encumbered ligands is extremely slow (requiring 5-14 days to completion). Development of a fast and selective diamidoamine catalyst with flanking N-SiMe₂Ph groups led to an expansion of the hydrazine scope and a structurally diverse set of hydrazones.

SUBMITTER: Karmakar PS 

PROVIDER: S-EPMC12453071 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature