Regio- and selective synthesis of 4,6-disubstituted-2-pyridones
摘要:
Palladium catalysed regio- and stereoselective annulation of allenyl stannanes by beta-iodo vinylic arnides gives good yields of the corresponding 2-pyridones. This annulation probably occurs via a Stille reaction/cyclisation sequence. (C) 2003 Elsevier Ltd. All rights reserved.
3,3-Disubstituted prop-2-enoic acids were selectively prepared in good yields under mild experimental conditions via palladium-catalysed cross-coupling of 3-substituted 3-iodobut-2-enoic acids with miscellaneous organometallic reagents using dichlorobis(acetonitrile)palladium(II) as catalyst and DMF as solvent.
Palladium-catalysed regio- and stereoselective annulation of allenyl stannanes by β-iodo vinylic acids gives the corresponding α-pyrones in high yields. This annulation most probably proceeds through a Stille reaction/cyclisation sequence.
A general route to α-pyrones and 3-substitutedisocoumarins from (Z)-iodovinylic acids 1a−f or 2-iodobenzoic acids 4a−c is described, including compounds bearing a substituent on the aromatic ring. Treatment of (Z)-β-iodovinylic acids 1a−f or 2-iodobenzoic acids 4a−c with various allenyltributyltin reagents in the presence of palladium acetate, triphenylphosphine, and tetrabutylammonium bromide in
This reviews surveys the preparation of a great diversity of complex biorelevant gamma-lactam backbones thanks to scalable copper(I)-catalyzed cascade multicomponent processes.
(<i>E</i>)-5-(Tributylstannylmethylidene)- 5<i>H</i>-furan-2-ones: Versatile Synthons for the Stereospecific Elaboration of γ-Alkylidenebutenolide Skeletons
[GRAPHICS]Stereoselective construction of (E)-gamma-tributylstannylmethylidene butenolides 1 was achieved through the palladium-catalyzed tandem cross coupling/cyclization reactions of tributylstannyl 3-iodopropenoate derivatives with tributyltinacetylene. Iododestannylation of 1 occurs with inversion of the configuration of the exocyclic double bond while the observed selectivity in the Stille reaction was found to be dependent on the nature of the aryl halide.