Mono- and 1,3-disubstituted allenes were synthesized from the corresponding propargylamines via palladium-catalysed hydride-transferreaction. In the current transformation, propargylic amines can be handled as allenyl anion equivalents and introduced into various electrophiles to be transformed into allenes under palladium-catalyzed conditions.
Effect of Varying the Anionic Component of a Copper(I) Catalyst on Homologation of Arylacetylenes to Allenes by the Mannich Reaction
作者:Vipan Kumar、Alex Chipeleme、Kelly Chibale
DOI:10.1002/ejoc.200700859
日期:2008.1
The effect of varying the anionic component of a copper(I) catalyst in the homologation of terminal arylacetylenes to allenes by the Mannichreaction was investigated. Varying amounts of allenes, Mannich bases and dimers were obtained depending on the nature of the anionic component of the copper catalyst. On the other hand, Eglinton–Glaser dimerizations were achieved in high yields with 0.5 equiv
trisubstituted allenesfrom propargyl alcohol is provided; the synthesis proceeds via an oxaphosphetane intermediate. Functional groups such as formyl and pyridyl exhibited a degree of tolerance during reaction without any protection. The alcohol dimethylated at the propargyl position afforded two structural isomers, allene and 1,3-diene. The product ratio was considerably influenced by the solvent. Allene was
Benzannulation from Alkyne without Metallic Catalysts at Room Temperature to 100 °C
作者:Tienan Jin、Fan Yang、Yoshinori Yamamoto
DOI:10.1021/ol902742u
日期:2010.1.15
An efficient, novel metal-catalyst-free aminobenzannulation of 2-(prop-2-ynyl)(oxo)benzenes 1 with various dialkylamines 2 afforded a variety of 2-aminonaphthalenes 3 in good to excellent yields under mild reaction conditions at room temperature to 100 degrees C (at most).