820250-67-7Relevant articles and documents
Nickel-catalyzed acylstannylation and alkynylstannylation of 1,2-dienes
Nakao, Yoshiaki,Shirakawa, Eiji,Tsuchimoto, Teruhisa,Hiyama, Tamejiro
, p. 3701 - 3721 (2007/10/03)
Carbostannylation of 1,2-dienes using acyl- and alkynylstannanes was achieved by means of nickel catalysis. In particular, acylstannylation of 1,2-dienes could be carried out with bis(1,5-cyclooctadiene)nickel [Ni(cod) 2] and acylstannanes to give selectively α-acylmethyl(vinyl) stannanes. The reaction was also applicable to acylstannanes prepared in situ by protonolysis of α-alkoxyalkenylstannanes or by reactions of α-silyloxyvinylstannanes with aldehyde acetals. For alkynylstannylation, a combination of Ni(cod)2 and 1,3-bis(diphenylphosphino)propane (dppp) was found to be effective to afford α-alkynylmethyl(vinyl)stannanes, whereas the Ni(cod)2-1,3-bis(dimethylphosphino)propane (dmpp) catalyst switched the regioselectivity to give (Z)-α- alkynylmethyl(alkenyl)stannanes. The acylstannylation products were successfully converted into various conjugated or unconjugated enones by a combination of cross-coupling and NaH-catalyzed isomerization. The alkynylstannylation products were transformed by cross- or homo-coupling reactions to various enynes or 2,3-bis(alkynylmethyl)-1,3-dienes, versatile precursors for variously substituted polycyclic compounds.