Alkoxide precoordination to rhodium enables stereodirected catalytic hydrogenation of a dihydrofuranol precursor of the C29-40 F/G sector of pectenotoxin-2
作者:Xiaowen Peng、Dmitriy Bondar、Leo A. Paquette
DOI:10.1016/j.tet.2004.06.142
日期:2004.10
enantioselective synthesis of the stereochemically fully endowed C(29-40) fragment of pectenotoxin-2 is detailed. The highlight of the synthesis is an alkoxide-directed hydrogenation in which ionic complexation of the deprotonated substrate to [Rh(NBD)(DIPHOS-4)]BF4, accomplished by the co-addition of an equivalent of sodium hydride in THF, completely deters a kinetic tendency for dehydration and properly
详细的立体化学合成的果胶毒素C(29-40)片段的对映体选择性合成。合成的重点是醇盐定向的氢化反应,其中去质子化的底物与[Rh(NBD)(DIPHOS-4)] BF 4的离子络合是通过将等价的氢化钠完全共添加到THF中来完成的。可以确定脱水的动力学趋势,并可以将关键的立体化学适当地设置在C-35上。通过这种催化技术实现的双重目标有望被广泛应用。