From 1,2-dialkoxyalkanes to 1,4-dioxanes. A transformation mediated by NbCl5via multiple C–O bond cleavage at room temperature

Abstract

The formation of 1,4-dioxanes and alkyl chlorides from the reactions of polyethers (dme, diglyme, 1,2-diethoxyethane, 1,2-dimethoxypropane) with NbCl₅ at room temperature is described; as far as dme is concerned, the reaction mainly occurs in two steps, consisting of (i) cleavage of one O–CH₃ bond, followed by (ii) cleavage of the second O–CH₃ bond and one of the two O–CH₂ linkages. The characterization of intermediate complexes and the isolation of NbOCl₃(dme) are reported.