Diverse Reactivity of Hypersilylsilylene with Boranes and Three-Component Reactions with Aldehyde and HBpin

• Published in: Inorganic chemistry 2021-02, Vol.60 (3), p.1654-1663
• Main Authors: Bisai, Milan Kumar, Swamy, V. S. V. S. N, Raj, K. Vipin, Vanka, Kumar, Sen, Sakya S
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.0c03137

The recently reported hypersilylsilylene PhC­(NtBu)2SiSi­(SiMe3)3 (1) reacts with BH3, 9-BBN, and PhBCl2 to yield the respective Lewis acid base adducts 2–4, respectively. Compound 4 undergoes isomerization to form a ring expansion product 5. The same silylene was found to initially form an adduct with HBpin (6) and subsequently isomerized to 7 via the rupture of the B–H bond of HBpin (7), where the hydride was bound to the carbon atom of the amidinate ligand and the Bpin unit was attached to the silicon center. Surprisingly, the reaction of 1 with HBcat results in PhC­(NtBu)2Bcat (8). Subsequently, we have shown that HBcat forms the same product when it reacts with related silylene PhC­(NtBu)2SiN­(SiMe3)3 (1′). With all of these reactions in hand, we ponder if silylene can activate two small molecules at one time. In this work, we delineate the three-component reactions of silylenes 1 and 1′ with 4-fluorobenzaldehyde and HBpin, which afforded unusual coupling products, 9 and 10, respectively. Note that 9 and 10 were prepared from the cleavage of the B–H and CO bonds by silylene in a single reaction and are the first structurally attested Si–C–O–B coupled products.