The palladium-tributylammonium formate reagent in the stereoselective hydrogenation, and stereo- and regioselective hydroarylation of alkyl 4-hydroxy-2-alkynoates: a route to substituted butenolides
The reaction of aryl iodides with alkyl 4-hydroxy-2-alkynoates in the presence of formic acid, tri-n-butylamine and a palladium(II) catalyst provides a convenient route to functionalized substituted butenolides through a one pot hydroarylation/cyclization reaction. In the presence of formic acid, tri-n-butylamine and a palladium(II) catalyst, alkyl 4-hydroxy-2-alkynoates undergo a one pot hydrogenation/cyclization
The Mukaiyama reaction of ketene bis(trimethylsilyl) acetals with α-halo acetals
作者:F.W.J. Demnitz
DOI:10.1016/s0040-4039(01)93317-9
日期:——
Ketene bis(trimethylsilyl) acetals were reacted with α-halo acetals giving β-alkoxy-γ-halo acids which were converted to butenolides by reaction with two equivalents of base. This constitutes a novel and short butenolide synthesis.
Butenolide Synthesis from Functionalized Cyclopropenones
作者:Sean S. Nguyen、Andrew J. Ferreira、Zane G. Long、Tyler K. Heiss、Robert S. Dorn、R. David Row、Jennifer A. Prescher
DOI:10.1021/acs.orglett.9b03298
日期:2019.11.1
A general method to synthesize substituted butenolides from hydroxymethylcyclopropenones is reported. Functionalized cyclopropenones undergo ring-opening reactions with catalytic amounts of phosphine, forming reactive ketene ylides. These intermediates can be trapped by pendant hydroxy groups to afford target butenolide scaffolds. The reaction proceeds efficiently in diverse solvents and with low catalyst
Tertiary propargylicalcohols reacted with carbon monoxide in the presence of catalytic quantities of a cationic palladium(II) complex, [Pd(CH3CN)2(PPh3)2](BF4)2, to afford 2(5H)-furanones and/or 2,3-dienoic acids, the precursor of the furanones, in good yields under mild conditions.