Ionic liquid catalyzed Ritter reaction/Pd-catalyzed directed Ortho-arylation; facile access to diverse libraries of biaryl-amides from Aryl-nitriles

Document Type

Article

Publication Date

12-10-2020

Abstract

Diverse libraries of biaryl-amides bearing N-t-butyl and N-adamantyl groups were synthesized in two steps by the Ritter reaction of aryl-nitriles, using tBuOH and AdaOH as carbocation precursors, and employing [BMIM(SO3H)][OTf] (neat or with [BMIM][PF6] as co-solvent) or tetramethyl guanidinium-ILs [TMG][X] (X = CF3COO, EtOSO3) as dual catalyst/solvent, followed by a Pd-catalyzed directed regioselective ortho[sbnd]C[sbnd]H arylation of the Ritter amides with Ar-X (X = I, Cl). The feasibility to perform the two-steps in sequence is also demonstrated, and potential for recycling/reuse of the ILs is also shown. Preference for [Pd] coordination to the amide carbonyl versus amide nitrogen is borne out by DFT computations.

Publication Title

Tetrahedron Letters

Volume

61

Issue

50

Digital Object Identifier (DOI)

10.1016/j.tetlet.2020.152553

ISSN

00404039

E-ISSN

18733581

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