Ru-NHC-Catalyzed Asymmetric, Complete Hydrogenation of Indoles and Benzofurans: One Catalyst with Dual Function

Abstract

The highly enantioselective and complete hydrogenation of protected indoles and benzofurans has been developed, affording facile access to a range of chiral three-dimensional octahydroindoles and octahydrobenzofurans, which are prevalent in many bioactive molecules and organocatalysts. Remarkably, we are in control of the nature of the ruthenium N-heterocyclic carbene complex and employed the complex as both homogeneous and heterogeneous catalysts, providing new avenues for its potential applications in the asymmetric hydrogenation of more challenging aromatic compounds.

Access to C(sp3) borylated and silylated cyclic molecules: hydrogenation of corresponding arenes and heteroarenes

“… 30 A cooperative heterogeneous and homogeneous strategy for asymmetric hydrogenations of arenes and heteroarenes has also been developed, which has been applied to a single borylated substrate (benzofuran). 31–33 The hydrogenation of fluoropyridines using Pd(OH) 2 , in acidic media has also been reported. 34 …”

“…30 A cooperative heterogeneous and homogeneous strategy for asymmetric hydrogenations of arenes and heteroarenes has also been developed, which has been applied to a single borylated substrate (benzofuran). [31][32][33] The hydrogenation of uoropyridines using Pd(OH) 2 , in acidic media has also been reported. 34 While we considered all prior art cited above, Glorius' results motivated us to fully evaluate bench stable and commercially available Rh-catalysts, e.g.…”

Dearomative pyrrole (3+2) reaction with geminal bromonitroalkane: synthesis of 2,3-dihydropyrroles

“…The 2,3,4,5,6,7-hexahydro-1 H -indole core in 3g′a could be converted into octahydroindole, which is a structural motif of marketed drugs (Perindopril and Odalasvir). 12 1-Boc-indole gave 3h′a in 53% yield.…”