Abstract
In an abundance of the previous papers methylene compounds linking two heteroatoms have proved to furnish versatilities and conveniences for syntheses of varied organic compounds. This article is an attempt to review the reactions of the compounds possessing methylene linking two N-, O- and S-functional groups, which bring on substitution of one group and insertion into one side. Particularly, one of the purposes of this article is to explain comprehensively the nature of the hetero-functional groups of the methylene compounds engaging in the reactions.
