Palladium-Catalyzed Decarboxylative ortho-Amidation of Indole-3-carboxylic Acids with Isothiocyanates Using Carboxyl as a Deciduous Directing Group.

Palladium-catalyzed ortho-amidation of indole-3-carboxylic acids with isothiocyanates by using the deciduous directing group nature of carboxyl functionality to afford indole-2-amides is demonstrated. Both C-H functionalization and decarboxylation took place in one pot, and hence, this carboxyl group served as a unique, deciduous (or traceless) directing group. This reaction offers a broad substrate scope as demonstrated for several other heterocyclic carboxylic acids like chromene-3-carboxylic acid, imidazo[1,2- a]pyridine-2-carboxylic acid, benzofuran-2-carboxylic acid, pyrrole-2-carboxylic acid, and thiophene-2-carboxylic acid.

Ruthenium-Catalyzed Oxidative Annulation and Hydroarylation of Chromene-3-carboxamides with Alkynes via Double C-H Functionalization.

Ruthenium-catalyzed oxidative annulation of 2H-chromene-3-carboxamides with alkynes has been achieved by using the directing group nature of amide in the presence of Cu(OAc)·HO as an oxidant and AgNTf as an additive. This reaction offers a broad substrate scope, and both symmetrical and unsymmetrical alkynes can be harnessed. High regioselectivity was achieved in the case of unsymmetrical alkynes.

Reactivity of alkynylindole-2-carboxamides in [Pd]-catalysed C-H activation and phase transfer catalysis: formation of pyrrolo-diindolones vs. β-carbolinones.

The divergent behaviour of 3-alkynylindole-2-carboxamides, under palladium catalysed conditions and phase-transfer catalytic conditions, is described. Thus, palladium catalysed intramolecular C-N and C-C bond formation in a single step by C-H activation involving 3-alkynylindole-2-carboxamides and leading to pyrrolodiindolones in high yields is developed. In contrast, using the same precursors, a high yielding regio- and chemo-selective route for 3-substituted β-carbolinones by phase-transfer catalysis is established via intramolecular C-N bond formation.

Spontaneous resolution upon crystallization of allenyl-bis-phosphine oxides.

The first example of 'spontaneous resolution by crystallization' in allene chemistry, by means of crystal structures and solid state CD spectra of the R and S enantiomers, is presented. These allenes are prepared by the simple reaction of Ph2PCl with o-nitro functionalized propargyl alcohols.