Update 1 of: Synthesis and Functionalization of Indoles Through Palladium-Catalyzed Reactions

Aminofluorination of 2-alkynylanilines: a Au-catalyzed entry to fluorinated indoles

The scope and limitations of gold-catalyzed tandem cycloisomerization/fluorination reactions of unprotected 2-alkynylanilines to have access to 3,3-difluoro-2-aryl-3H-indoles and 3-fluoro-2-arylindoles are described. An unprecedented aminoauration/oxidation/fluorination cascade reaction of 2-alkynylanilines bearing a linear alkyl group on the terminal triple bond is reported.

Concise syntheses of meridianins and meriolins using a catalytic domino amino-palladation reaction

A synthesis of natural and synthetic members of the meridianin family of kinase inhibitory natural products has been developed. The sequence utilizes a variation of the Cacchi palladium-catalyzed domino reaction to efficiently construct the heterocyclic framework of the meridianins and meriolins from monocyclic precursors.

Stereoselective synthesis of C-fused pyranoindoles, pyranobenzofurans and pyranobenzothiophene scaffolds using oxa-Pictet–Spengler type reaction of vinylogous carbonates

C-fused pyranoheterocycles can be assembled in a highly diastereoselective manner using an intramolecular oxa-Pictet–Spengler type reaction of vinylogous carbonates.

Copper-catalyzed annulation of α-substituted diazoacetates with 2-ethynylanilines: the direct synthesis of C2-functionalized indoles

Copper-catalyzed direct annulation of α-substituted diazoacetates with 2-ethynylanilines leading to C2-functionalized indoles was achieved under mild reaction conditions. The C2-(carboxylate methyl) substituted indoles were obtained in moderate to high yields.

Choline chloride based eutectic solvents: direct C-3 alkenylation/alkylation of indoles with 1,3-dicarbonyl compounds

C-3 alkenylation/alkylation of indoles depends on the position of the substituent on the indole used in the reaction.

Facile regiospecific synthesis of 2,3-disubstituted indoles from isatins

A facile regiospecific synthesis of 2,3-disubstituted indoles from isatins has been developed.

BippyPhos: a single ligand with unprecedented scope in the Buchwald-Hartwig amination of (hetero)aryl chlorides

Over the past two decades, considerable attention has been given to the development of new ligands for the palladium-catalyzed arylation of amines and related NH-containing substrates (i.e., Buchwald-Hartwig amination). The generation of structurally diverse ligands, by research groups in both academia and industry, has facilitated the accommodation of sterically and electronically divergent substrates including ammonia, hydrazine, amines, amides, and NH heterocycles. Despite these achievements, problems with catalyst generality persist and access to multiple ligands is necessary to accommodate all of these NH-containing substrates. In our quest to address this significant limitation we identified the BippyPhos/[Pd(cinnamyl)Cl]2 catalyst system as being capable of catalyzing the amination of a variety of functionalized (hetero)aryl chlorides, as well as bromides and tosylates, at moderate to low catalyst loadings. The successful transformations described herein include primary and secondary amines, NH heterocycles, amides, ammonia and hydrazine, thus demonstrating the largest scope in the NH-containing coupling partner reported for a single Pd/ligand catalyst system. We also established BippyPhos/[Pd(cinnamyl)Cl]2 as exhibiting the broadest demonstrated substrate scope for metal-catalyzed cross-coupling of (hetero)aryl chlorides with NH indoles. Furthermore, the remarkable ability of BippyPhos/[Pd(cinnamyl)Cl]2 to catalyze both the selective monoarylation of ammonia and the N-arylation of indoles was exploited in the development of a new one-pot, two-step synthesis of N-aryl heterocycles from ammonia, ortho-alkynylhalo(hetero)arenes and (hetero) aryl halides through tandem N-arylation/hydroamination reactions. Although the scope in the NH-containing coupling partner is broad, BippyPhos/[Pd(cinnamyl)Cl]2 also displays a marked selectivity profile that was exploited in the chemoselective monoarylation of substrates featuring two chemically distinct NH-containing moieties.