nickel/Lewis acid (LA) cooperative catalysis to give beta-cyano-substituted acrylates and acrylamides, respectively, in highly stereoselective and regioselective manners. The resulting adducts serve as versatile synthetic building blocks through chemoselective transformations of the ester, amide, and cyano groups as demonstrated by the synthesis of typical structures of beta-cyano ester, beta-amino
Total Synthesis of Aigialomycin D: Surprising Chemoselectivity Dependence on Alkyne Structure in Nickel-Catalyzed Cyclizations
作者:Christa C. Chrovian、Beth Knapp-Reed、John Montgomery
DOI:10.1021/ol702961v
日期:2008.3.1
The totalsynthesis of aigialomycin D was carried out using a nickel-catalyzed ynal macrocyclization as a key step. This key step allowed macrocycle assembly and formation of a disubstituted alkene and a secondary hydroxyl stereocenter in a single step, although the stereocenter was formed unselectively. An interesting side reaction involving five-membered-ring synthesis by an aldehyde/styrene cyclization
A series of 66 new indolone-N-oxide derivatives was synthesized with three different methods. Compounds were evaluated for in vitro activity against CQ-sensitive (3D7), CQ-resistant (FcB1), and CQ and pyrimethamine cross-resistant (K1) strains of Plasmodium falciparum (P.f.), its well as for cytotoxic concentration (CC50) on MCF7 and KB human tumor Cell lines. Compound 26 (5-methoxy-indolone-N-oxide analogue) had the most potent antiplasmodial activity in vitro (< 3 nM on FcB1 and = 1.7 nM on 3D7) with a very satisfactory selectivity index (CC50 MCF7/IC50 FcB1: 14623; CC50 KB/IC50 3D7: 198823). In in vivo experiments, compound 1 (dioxymethylene derivatives of the indolone-N-oxide) showed the best antiplasmodial activity against Plasmodium berghei, 62% inhibition of the parasitaemia at 30 mg/kg/day.
A mild preparation of vinyliodides from vinylsilanes
作者:Dean P Stamos、Andrew G Taylor、Yoshito Kishi
DOI:10.1016/s0040-4039(96)02000-x
日期:1996.11
A new method for the synthesis of vinyliodides from vinylsilanes is presented. Using N-iodiosuccinimide in acetonitrile or acetonitrile/monochloroacetonitrile, this transformation is cleanly effected at room temperature under virtually neutral conditions. Copyright (C) 1996 Elsevier Science Ltd
Preparation of 2,2-Dichloro-3(2H)-furanone and Its Reactions with Heteronucleophiles