The use of palladium catalysis for the formation of fused aromatic compounds and for the diastereoselective formate reduction of allylic carbonates.

摘要

The use of palladium-catalyzed reactions for the preparation of bicyclic compounds and propionate units is described in this thesis.; Chapter 1 describes the formation of fused aromatic bicyclic systems using palladium-catalyzed domino reactions. The effect of substitution on both partners, i.e. the aryl iodide and the bromoenoate, was evaluated. Numerous functional groups are tolerated (alkyl, aryl, halide, protected alcohol, amide, amine, etc.), allowing for a quick and convergent access to functionalized aromatic bicyclic compounds. This methodology was extended toward the preparation of 1-substituted-3-benzoxepines and 1,4-disubstituted-3-benzoxepines and preliminary results were obtained from the synthesis of 1-substituted-3-benzoxepines. Finally, a variant of this reaction where the alkyl bromide is tethered to the aryl iodide was briefly explored.; Chapter 2 examines the diastereoselective reduction of allylic carbonates using formic acid for the synthesis of propionate units. The diastereoselectivity of the reaction was significantly improved by modifying the reaction conditions. The influence of the protecting group, leaving group, olefin geometry, and nearby substitution was also evaluated. The use of silyl protecting groups with the appropriate allylic carbonate substrates allows for the preparation of the syn-syn and anti-syn triads in synthetically useful diastereoselectivity. Preliminary results also indicate that the synthesis of the syn-anti and anti-anti triads is also possible, albeit in low dr.