Hydrazides as Tunable Reagents for Alkene Hydroamination and Aminocarbonylation
摘要:
Benzoic hydrazides (R = Ph), which are remarkably bench and thermally stable reagents (often up to 230 degrees C), afford intramolecular hydroamination products upon heating at high temperatures (120-235 degrees 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 degrees C, and the tatter reaction is shown to be stereospecific.
Improved Cope-type hydroamination reactivity of hydrazine derivatives
作者:Francis Loiseau、Christian Clavette、Michaël Raymond、Jean-Grégoire Roveda、Alishya Burrell、André M. Beauchemin
DOI:10.1039/c0cc02403a
日期:——
A systematic investigation on the metal-free, Cope-type hydroamination reactivity of hydrazides and analogues is reported. Optimization of the hydrazide structure resulted in more facile intramolecular reactivity and enabled intermolecular reactions of alkenes, thus providing a direct approach to polysubstituted hydrazides.