Microwave-assisted efficient one-pot synthesis of 9-phenyl-9,10- disilatriptycene and its bridgehead functionalization

9-Phenyl-9,10-disilatriptycene (2) was synthesized by the reaction of bis(2-bromophenyl)silane (1) with magnesium in THF. On conventional heating, 2 and cis-9,10-diphenyl-9,10-dihydro-9,10-disilaanthracene (cis-3) were obtained in 31% and 36% yields, respectively. However, the yield of 2 was significantly increased to 71% on microwave irradiation. Theoretical calculations suggest that the intermediary Grignard reagents generated from trans- and cis-9,10-diaryl-9,10-dihydro-9,10-disilaanthracenes have quite different reactivity for construction of the 9,10-disilatriptycene skeleton. The bridgehead Si-H moiety of 2 was readily functionalized to give several 9,10-disilatriptycene derivatives.