Tri(pentaflurophenyl)borane-catalyzed reduction of cyclic imides with hydrosilanes: Synthesis of pyrrolidines
B(C6F5)3-catalyzed hydrosilylation of cyclic imides afforded an efficient synthetic method of pyrrolidines. In the presence of 5 mol% B(C6F5)3, various aromatic, aliphatic and polycyclic imides were smoothly reduced by PhSiH3 to generate the corresponding pyrrolidines in high yields. The reaction profiles monitored by 1H NMR spectroscopy disclosed the reduction process of cyclic imides and the effect of difference structure of the hydrosilanes on the hydrosilylation.
Alkoxide-Catalyzed Hydrosilylation of Cyclic Imides to Isoquinolines via Tandem Reduction and Rearrangement
An alkoxide-catalyzed hydrosilylation of cyclic imides to isoquinolines was realized via tandem reduction and rearrangement. Using TMSOK as the catalyst and (EtO)2MeSiH as the reductant, a series of cyclic imides containing different functional groups were reduced to the corresponding 3-aryl isoquinolines in moderate to good yields. The scenario of the reaction pathway was supposed to involve the reduction of imides to ω-hydroxylactams, which underwent rearrangement in the presence of a base catalyst, and then the carbonyl reduction, followed by siloxy elimination.