Hydrazides as Tunable Reagents for Alkene Hydroamination and Aminocarbonylation

Benzoic hydrazides (R = Ph), which are remarkably bench and thermally stable reagents (often up to 230 °C), afford intramolecular hydroamination products upon heating at high temperatures (120−235 °C). A concerted Cope-type hydroamination event, followed by a hydrazide-mediated proton transfer step of the hydrazinium ylide intermediate, is proposed and supported by DFT calculations. In contrast, a simple modification of the reagent structure (R = Ot-Bu or NH2) favors the formation of aminocarbonylation products at 200 °C, and the latter reaction is shown to be stereospecific.