Synthetic utilization of alpha-phosphonovinyl anions

The alpha-phosphonovinyl anions, generated in situ from treatment of beta-h etero-substituted vinylphosphonates la-e with LDA (or LTMP), were trapped w ith various electrophiles such as chlorotriorganosilanes, chlorotrimethylge rmane, chlorotriorganotins, dimethyl disulfide, and halogen to afford the c orresponding beta-hetero-substituted alpha-functionalized vinylphosphonates 2-14 in good to excellent yields. The Friedel-Crafts reaction of alpha-(si lyl) or alpha-(germyl)phosphonoketene dithioacetals 2, 9 or 4 with acid chl orides gave alpha-acylated phosphonoketene dithioacetals 15-19 in 53-91% yi elds. The palladium-catalyzed cross-coupling reaction of beta-ethoxy-alpha- (tributylstannyl)vinylphosphonate 13 with a variety of organic halides (R=a cyl, allyl, aryl etc.) provided beta-ethoxy-alpha-substituted vinylphosphon ates 20-25 in good to moderate yields. The palladium-mediated cross-couplin g reaction of alpha-(iodo)-vinylphosphonates 7, 14 with terminal acetylenes afforded alpha-alkynylated vinylphosphonates 26-29 in 69-83 % yields.