The Pd-catalyzed cross-coupling of allylic carbonates and allyIB(pin) is described. The regioselectivity of this reaction is sensitive to the bite angle of the ligand, with small-bite-angle ligands favoring the branched substitution product. This mode of regioselection is consistent with a reaction that operates by a 3,3' reductive elimination reaction. In the presence of appropriate chiral ligands, this reaction is rendered enantioselective and applies to both aromatic and aliphatic allylic carbonates.
The reduction of the carbonyl group in acylated trifluoroethyl alkanesulfonates follows the Felkin-Ahn selectivity, and the so-formed diastereomeric β-hydroxysulfonyl intermediates undergo syn- and anti-fragmentation, depending on the reaction conditions. In effect, isomeric E- and Z-alkenes are formed in a stereodivergent manner, which mimics the mechanistic manifold of the Peterson olefination.
A platinum-support zeolite coupled with a silica layer was prepared by Chemical Vapor Deposition (CVD) of tetraethoxysilane, and was investigated in order to determine the catalytic characterization in an analysis of the surface. With this catalyst system, it was demonstrated that the terminal carbon–carbon double bond is preferentially hydrogenated in the case of several unsaturated hydrocarbons. Further, it was elucidated that a highly regioselective hydrogenation of compounds which possess plural double bonds was achieved over this catalyst system. As a result, a reaction model regarding this catalyst system has been put forward.