Reactions of Heteroallenes with Salan-based Ti(IV) Complexes: A Joint Experimental and Computational Study

Chem Asian J. 2024 Feb 25:e202400165. doi: 10.1002/asia.202400165. Online ahead of print.

Abstract

The reaction of Ti(NMe2 )4 with the salan ligand precursor H2 N2 O2 H2 led to the formation of [(L*)Ti(NHMe2 )2 ] (L*=N2 O2 4- ) that forms [(H2 N2 O2 )TiCl2 ] upon reaction with two equiv. of Me3 SiCl. [(L*)Ti(py)2 ] was obtained from the reaction of [Ti(Nt Bu)Cl2 (py)3 ] with the sodium salt H2 N2 O2 Na2 . Treatment of [(L*)Ti(NHMe2 )2 ] with two equiv. of t BuNCO led to the insertion of the isocyanate molecules into the Ti-Nsalan bonds with the formation of [{L*(N(t Bu)CO)2 }Ti]. Conversely, the reaction of [(H2 N2 O2 )Ti(Oi Pr)2 ] with two equiv. of t BuNCO led to the insertion of one isocyanate molecule into a Ti-Nsalan bond with the formation of [{(HN2 O2 )(N(t Bu)CO)}Ti(Oi Pr)]. Computational studies were performed to gain insight into the reactivity of isocyanates with salan-based Ti(IV) complexes.

Keywords: DFT calculations; Ti-salan complexes; carbon dioxide; insertion reactions; isocyanates.