Synthesis of an N‐Heterocylic Boryl‐Stabilized Disilyne and Its Application to the Activation of Dihydrogen and C−H Bonds
Yazhou Ding, Yang Li, Jianying Zhang, Chunming Cui
Abstract
Abstract The synthesis of low‐valent silicon compounds that enable the activation of small molecules has been of great current interest. Reduction of N‐heterocyclic boryltribromosilane (NHB)SiBr 3 ( 2 , NHB=[ArN(CMe) 2 NAr]B, Ar=2,6‐ i Pr 2 C 6 H 3 ) with three equiv. of lithium in diethyl ether yielded the NHB‐stabilized disilyne (NHB)Si≡Si(NHB) ( 3 ). Disilyne 3 slowly reacted with toluene, leading to the activation of one benzylic C−H bond and one C=C double bond with the formation of 4 . Treatment of 3 with dihydrogen under 1 atm at room temperature resulted in the exclusive formation of the first boryl‐stabilized 1,2‐dihydrodisilene. Compounds 3 – 5 have been characterized by single‐crystal X‐ray diffraction studies, which indicated the co‐planarity of the B−Si−Si−B plane with the NHB rings in compounds 3 and 5 . DFT calculations indicated the significant π electron delocalization of the Si−Si multiple bonds to the B−N bonds in NHB rings.