A highly regio-and stereoselective Heck reaction of iodoarenes with vinylated malonates, generated in situ by fluorideinduced protiodesilylation of alkenylsilanols/disiloxanes to give functionalized styrenes and 1,4-diaryl-1-butenes has been developed. The dibenzylbutyrolactone lignan skeletons have been achieved from 1,4-diaryl-1-butenes by two routes

An efficient method for the quantitative conversion of 1-substituted alkenyl(phenyl)silanes into the corresponding alkenylsilanols has been developed and used in their palladium(0)-catalyzed, tetrabutylammonium fluoride-promoted cross-coupling reaction with aryl iodides. Copper(I) chloride

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Polyphenylalkene derivatives Q 0740 A Novel Approach to Functionalized (E)-1,4-Diaryl-1-butenes by Heck Reaction and Their Applications for the Construction of Dibenzylbutyrolactone LignanSkeletons by Radical Cyclization. -Terminal olefins, generated in situ by protodesilylation of a mixture of silanols (I) and disiloxanes (II), undergo Pd-catalyzed regioand stereoselective Heck reaction with aryl iodides to give the (E)-butenes (IV) in good yield. The utility of these products is demonstrated by conversion of (IVc) to the lignans (VI)/(VII) and (IX)/(X). -(SINGH, R.; SINGH, G. C.; GHOSH*, S. K.; Tetrahedron Lett. 46 (2005) 28, 4719-4722; Bio-Org. Div., Bhabha At. Res. Cent., Mumbai 400 085, India; Eng.) -Mais 43-107

±)-Matairesinol Synthesis. -A highly regioand stereoselective Heck reaction of iodoarenes to vinylated malonates is presented. The reaction provides a diversity of styrene and diarylbutene derivatives (V) in good yields. The transformation of these diarylbutenes into dibenzylbutyrolactones (VII)/ (VIII) and (X)/(XI) is achieved on two pathways involving radical cyclization of a selenylmethyl ester (VI) or a selenocarbonate (IX) as the key step. Lactone (VIIIa) is easily debenzylated to matairesinol (XII). -(SINGH, R.; SINGH, G. C.; GHOSH*, S. K.; Eur.