91879-80-0Relevant academic research and scientific papers
Silicon tetrachloride in organic synthesis: New applications for the vinylogous aldol reaction
Acocella, Maria R.,De Rosa, Margherita,Massa, Antonio,Palombi, Laura,Villano, Rosaria,Scettri, Arrigo
, p. 4091 - 4097 (2007/10/03)
This paper describes a novel and efficient methodology for vinylogous aldol reactions based on SiCl4 catalysis. According to the nucleophilicity Mayr's scale, vinylogous aldol reaction of Chan's diene proved to be effective by using catalytic amount of SiCl4, without any other promoter. On the contrary, the SiCl4/Lewis base system has been conveniently exploited for the efficient and selective vinylogous reaction of less nucleophilic Danishefsky's diene and 2-trimethylsilyloxyfuran (TMSOF). Indeed, a number of Lewis bases, such as sulfoxides, formamides and phosphoramides have been successfully used as SiCl4 promoters. TMSOF and silyloxydienes, resulting from 2,2,6-trimethyl-[1,3]-dioxin-4-one derivatives, required stoichiometric amount of SiCl4, while vinylogous aldol reaction of Chan's and Danishefsky's dienes took satisfactorily place in the presence of catalytic or sub-stoichiometric amount of catalyst.
ON THE MECHANISM OF THE LEWIS ACID CATALYZED CYCLOCONDENSTION OF ALDEHYDES WITH SILOXYDIENES
Larson, Eric R.,Danishefsky, Samuel
, p. 1975 - 1978 (2007/10/02)
Competing cycloaddition versus aldolization-cyclization processes are demonstrated in the formation of 6-styryl-5,6-dihydro-γ-pyrone via the BF3 catalyzed reaction of cinnamaldehyde with trans-1-methoxy 3-trimethylsilyloxy-1,3-butadiene.
