A Lewis Acid-Base Pair Catalyzed Dearomative Transformation of Unprotected Indoles via B-H Bond Activation

A sustainable and metal-free protocol has been described for the reduction of unprotected indoles. The catalytic system consists of B(C6F5)3 and THF as a Lewis acid-base pair that can activate the B-H bond of pincolborane (HBpin). The catalytic system encompasses a broad substrate scope. Control experiments were conducted to understand the possible catalytic intermediates involved during the present protocol. Metal-free reduction: A sustainable and cost-effective protocol has been developed for the hydroboration of unprotected indoles. The present catalytic system contains B(C6F5)3 and THF as a Lewis pair, which can activate the B-H bond of pincolborane followed by hydroboration of unprotected indoles.image

Automated summary

A metal-free and sustainable method has been developed for the reduction of unprotected indoles. The catalytic system, consisting of B(C6F5)3 and THF as a Lewis acid-base pair, can activate the B-H bond of pincolborane. The catalytic system shows a broad substrate scope. Control experiments were conducted to understand the possible catalytic intermediates involved.