PdCl2-Catalyzed Efficient Transformation of Propargylic Amines to (E)-α-Chloroalkylidene-β-lactams
摘要:
The PdCl2-catalyzed cyclocarbonylation reaction of propargylic amines with CuCl2 and benzoquinone afforded (E)-alpha-chloroalkylidene-beta-lactams in moderate to good yields. The formation of the corresponding Z-isomers or five-membered products was not observed. The reaction of the readily available optically active propargylic amines provides a convenient synthesis of the corresponding (E)-alpha-chloroalkylidene-beta-lactams with high ee values. The structure and the stereochemistry of the products were established by the X-ray single-crystal diffraction study of (E)-6d and (E)-6e, which indicates that the stereoselectivity in this reaction is different from what was observed with propargylic alcohols. A rationale for this reaction was proposed.
PdCl2-Catalyzed Efficient Transformation of Propargylic Amines to (E)-α-Chloroalkylidene-β-lactams
摘要:
The PdCl2-catalyzed cyclocarbonylation reaction of propargylic amines with CuCl2 and benzoquinone afforded (E)-alpha-chloroalkylidene-beta-lactams in moderate to good yields. The formation of the corresponding Z-isomers or five-membered products was not observed. The reaction of the readily available optically active propargylic amines provides a convenient synthesis of the corresponding (E)-alpha-chloroalkylidene-beta-lactams with high ee values. The structure and the stereochemistry of the products were established by the X-ray single-crystal diffraction study of (E)-6d and (E)-6e, which indicates that the stereoselectivity in this reaction is different from what was observed with propargylic alcohols. A rationale for this reaction was proposed.
Optically Active 2,3-Allenoates<i>via</i>Palladium-Catalyzed Carbonylation of Enantioenriched Propargylic Mesylates
作者:Yuli Wang、Shengming Ma
DOI:10.1002/adsc.201200910
日期:2013.3.11
Under mild conditions, opticallyactive 2,3‐allenoates were synthesized from enantioenrichedpropargylicmesylates with moderate to excellent yields and high efficiency of chirality transfer by using palladium(0) bis(dibenzylideneacetone) (3 mol%) with (S)‐(−)‐5,5′‐bis(diphenylphosphino)‐4,4′‐bi‐1,3‐benzodioxole [(S)‐SEGPHOS] (3 mol%) as the catalyst and diammonium hydrogen phosphate (1.1 equiv .)