Manganese-Promoted Ring-Opening Hydrazination of Cyclobutanols: Synthesis of Alkyl Hydrazines.

We herein disclose an efficient manganese-promoted hydrazination of cyclobutanols through cyclic C-C bond cleavage. The ring opening occurs under mild reaction conditions, readily affording a variety of alkyl hydrazines in synthetically useful yields and exclusive regioselectivities. The chain reaction mechanism involving the addition of alkyl carbon radical to azodicarboxylate is proposed.