Alternatives to organic solvent: Organometallic reactions in novel media
Description
Section one. Contrary to previous studies, tin was found to mediate carbonyl allylation in water without the use of any activators such as acid or sonication Section two. Intramolecur aqueous Barbier-Grignard reaction methodology was applied to cyclic systems and used to expand the rings by one carbon Section three. An attempted synthesis of a polysaccharide mimic had as a key step the aqueous, metal-mediated addition of 2,3-dichloropropene to an aldehyde. Attempts to cyclize the monomer precursor by means of iodo-cyclization simply led to the deprotection of a TBDMS protected alcohol Section four. Barbier-Grignard carbonyl allylation reactions mediated by indium, tin, and zinc under neat conditions were studied. Indium was found to mediate the reaction well and was applied to a variety of aldehydes. Zinc and tin were also found to mediate the reactin, although less effectively than indium Section five. Liquid carbon dioxide was found to be an excellent solvent for the indium-mediated Barbier-Grignard reaction, in which allyl bromide was coupled with various aldehydes. Among the aldehydes successfully allylated was the solid 4-cyanobenzaldehyde, which had proved impossible to allylate under neat conditions Section six. Allylic alcohols were successfully isomerized in water using a water-soluble Ru (II) catalyst. Upon completion of the reaction, the product was removed by extraction with ether, leaving behind the aqueous catalytic solution, which was then ready for the next reaction. The catalytic solution was recycled five times with no apparent attrition of its catalytic ability