Manganese-catalyzed dehydrogenative coupling of silanes and hydroxyl compound controlled by phosphine oxide

Dehydrogenative coupling of silanes and hydroxyl compounds is a use-ful method for accessing compounds containing an Si-O bond. Along-side previous advances, practical and large-scale dehydrogenative coupling catalyzed by an available and cheap catalytic system remains appealing. Here, we report a general dimanganese decacarbonyl-cata-lyzed dehydrogenative coupling of silanes and hydroxyl compounds with inexpensive phosphine oxide ligands. This dehydrogenative coupling features a broad substrate scope of hydroxyl compounds, producing the corresponding silyl ethers and silanols in moderate to high yields (>91 examples, up to 99% yield). N-silylated indoles are also successfully synthesized by direct dehydrogenative coupling of N-H bonds and silanes. This reaction can be achieved on a 40 g scale with only 2.5 mol % of the manganese catalyst, delivering the desired silyl ether in a quantitative yield without any isolation difficulties. In exploration of the mechanism, we find a probable and uncommon organometallic pathway controlled by the phosphine oxide ligand.

Automated summary

In this study, a dimanganese decacarbonyl-catalyzed dehydrogenative coupling of silanes and hydroxyl compounds has been developed using inexpensive phosphine oxide ligands. The reaction exhibits a broad substrate scope and yields the corresponding silyl ethers and silanols in moderate to high yields (>91 examples, up to 99% yield). Additionally, N-silylated indoles are successfully synthesized through direct dehydrogenative coupling of N-H bonds and silanes. Mechanistic studies reveal an unusual organometallic pathway controlled by the phosphine oxide ligand.