Application of Mutualism in Organic Synthetic Chemistry: Mutually Promoted C−H Functionalization of Indole and Reduction of Quinoline

Abstract

Here we reported a one‐pot, metal‐free B(C6F5)3‐catalyzed strategy for simultaneous synthesis of C3‐regioselective functionalization of indoles and complete reduction of quinolines. It turned out that by sharing a quinolinium hydridoborate intermediate, the original determining steps with high energy barrier in both the convergent disproportionation of indole and reduction of quinoline could be realized at room temperature, thus furnishing both the C3‐borylated (or silylated) indoles and N‐borylated tetrahydroquinolines in up to 98% yields at room temperature. Mechanistic studies suggested that both reactions would consume a product generated from the other reaction such that they can mutually promote each other, thus producing desirable products in a high atom‐economy and low energy‐cost manner. This strategy opened the gate to introducing mutualism to the field of chemistry.

Direct synthesis of sila-benzoazoles through hydrosilylation and rearrangement cascade reaction of benzoazoles and silanes

“…7b and 7c and DFT results 11,44 . The concerted activation of the Si-H bond in Ph 2 SiH 2 by B(C 6 F 5 ) 3 and 1a is similar to that in hydrosilylation/hydroboration reactions catalyzed by B(C 6 F 5 ) 3 reported previously [45][46][47][48][49][50] .…”

Application of HSAB Theory in the Selective Reduction of Quinoline

“…utilized B(C 6 F 5 ) 3 to rapidly polymerize α‐diketone and bis(silane) monomers into high molecular weight poly(silyl‐ether)s under ambient conditions. [ 54 ] After analyzing the previous literatures and our research work related to the boron chemistry, [ 55‐59 ] we focused our research interests on the design and development of new element reactions for polymer synthesis.…”

Recent Advances in Catalysis Using Organoborane-Mediated Hydride Abstraction

“…In our previous review, 6 we observed how hydride abstraction had been utilized in the dehydrogenation of a variety of benzofused N -heterocycles, 29 as well as the dehydrogenative coupling of indoles with silanes and boranes. These reactions are believed to proceed via an acceptorless dehydrogenation pathway, where an ammonium borohydride intermediate (generated after hydride abstraction and iminium tautomerization) undergoes an acid–base reaction to evolve H 2 .…”