Reaction of the lithio-derivative of methoxyallene with hydrazones. Part 1: Synthesis and transformation of α-allenyl hydrazines
作者:Valérie Breuil-Desvergnes、Jacques Goré
DOI:10.1016/s0040-4020(01)00030-8
日期:2001.3
methoxyallene reacts with aldehyde hydrazones leading to expected α-allenyl hydrazines when ether is the solvent of the reaction. The yields are good as well as the diastereoselectivity observed in the case of SAMP-hydrazones. These hydrazines are cleanly transformed to N-dialkylamino-3-methoxy-3-pyrrolines when they are reacted with n-BuLi in THF. These compounds are sometimes accompanied by the isomeric
Pinacolborane as the Boron Source in Nitrogen-Directed Borylations of Aromatic <i>N</i>,<i>N</i>-Dimethylhydrazones
作者:Rocío López-Rodríguez、Abel Ros、Rosario Fernández、José M. Lassaletta
DOI:10.1021/jo301965v
日期:2012.11.2
A mild procedure for the Ir(III)-catalyzed nitrogen-directed ortho borylation of aromatic N,N-dialkylhydrazones using pinacolborane as the boron source has been developed. The methodology relies on a modified, hemilabile N,N ligand built on a 4-N,N-dimethylaminopyridine unit that provides high reactivity while maintaining exclusive ortho-selectivity. This procedure can be combined with Suzuki–Miyaura
Reaction of the lithio-derivative of methoxyallene with hydrazones. Part 2: Formation of 3-pyrrolines and azetidines; synthetic and mechanistic aspects
作者:Valérie Breuil-Desvergnes、Jacques Goré
DOI:10.1016/s0040-4020(01)00031-x
日期:2001.3
3-pyrrolines when the time and temperature of the reaction are increased, but the rate of this transformation depends on the substituents of the terminal nitrogen. A reaction mechanism is proposed which involves intermolecular or intramolecular electron transfers from the lithium amide leading to hydrazinyl radicals. The relative stabilities of these intermediates may then explain the role of the substituents