Reactions of Secondary Allylamines with Bis(eta(5):eta(1)-pentafulvene)titanium Complexes: Selective Formation of Monoazabutadiene Titanium Complexes by N-H and C-H Bond Activation

摘要

The N-H and C-H bond activation reactions at ambient conditions of seven different secondary allyl amines (Aa-g) with bis(eta(5):eta(1)-pentafulvene)titanium complexes (1) have been investigated. Bis(eta(5):eta(1)-adamantylidenepentafulvene)titanium (1a) reacts with N-allylaniline (Aa), N-allylbenzylamine (Ac), N-allyl-tert-butylamine (Ad), N-allylcyclohexylamine (Ae), and N-allyl-2-methylaniline (Af) to give the 1-azabutadiene complexes 2a,cf with high yields. They are the first complexes of the CH2-terminated monoazadiene RN = CHCH = CH2. Using bis(eta(5):eta(1)-di-p-tolylpentafulvene)titanium (1b), which exhibits a less Bronsted basic C-exo center, and Aa, the beta-C-H bond activation can be slowed down so much that the agostic interaction between the titanium center and the C-H bond is detectable via NMR measurements at room temperature. In the reactions of the titanium azabutadiene complexes 2a,b and 3a with carbon monoxide a ligand exchange is observed, forming the titanocene dicarbonyls 4a,b.