Solution and Solid-State Structures of Lithiated Phenyloxazolines

Abstract

The structures of three ortho -lithiated phenyloxazolines, the parent ( 1 ), the para-tert -butyl analogue ( 2 ), and the para- chloro analogue ( 3 ), were studied in solution. All three compounds are mixtures of monomers and dimers in THF/ether mixed solvents, with 2 the most aggregated and 3 the least. They are converted to monomers with HMPA and PMDTA. In the PMDTA complexes, the lithium appears to still be chelated to the oxazoline ring. Single-crystal X-ray structures were obtained for 1 and 2 . Both are centrosymmetric dimers of B-type (each lithium coordinated to one oxazoline ring).