2,3-migration in Rh(II)-catalyzed reactions of beta-trifluoroacetamido alpha-diazocarbonyl compounds

Oxidative Addition to the N-C Bond Vs Formation of the Zwitterionic Intermediate in Platinum(II)-Catalyzed Intramolecular Annulation of Alkynes to Form Indoles: Mechanistic Studies and Reaction Scope

In this study, Pt(II)-catalyzed intramolecular translocation annulation of ortho-alkynylamides to the formation of indoles is presented, where a proposed intermediacy of zwitterionic intermediate has been substantiated over the oxidative addition. We focused our attention on Pt(II)-catalyzed aminoacylation of alkynes both theoretically and experimentally using low boiling solvent where the formation of deacylation product was suppressed simultaneously. One-step intramolecular [1,3]-acyl migration from the zwitterionic intermediate is highly unlikely, which imparts a high energy barrier of +99.0 kcal mol^-1. Another possible approach involving oxidative addition to the N-C bond, migratory insertion to alkyne, and subsequent reductive elimination is also explored through DFT studies to justify the reaction consequence. However, based on the computational studies, it is suggested that initial zwitterion formation is highly favored over oxidative addition. We suggest the formation of an acylium intermediate, which can further react with indol-3-ylplatinum species in an intramolecular manner, albeit within the same solvent cage to form 3-acyl indoles.

Rhodium-catalyzed denitrogenative transannulation of 1,2,3-triazolyl-carbamates: efficient access to 4-aminooxazolidinones

The rhodium(ii)-catalyzed denitrogenative transannulation reaction of 1,2,3-triazolyl-carbamates was described providing an efficient access to biologically interesting 4-aminooxazolidinones in excellent yields and selectivities.

Regiospecific and highly stereoselective synthesis of β-amino (Z)-enylphosphonates via β-hydrogen migration reaction of dialkyl α-diazophosphonates catalyzed by AgOTf

The diazo decomposition of dialkyl α-diazophosphonates in the presence of AgOTf provides an efficient one-step route to a variety of β-amino (Z)-enylphosphonates in good yields with complete control over regio- and stereochemistry.

Pyridine group assisted addition of diazo-compounds to imines in the 3-CC reaction of 2-aminopyridines, aldehydes, and diazo-compounds

A novel three-component coupling (3-CC) reaction of 2-aminoazines, aromatic aldehydes, and diazo-compounds producing polyfunctional β-amino-α-diazo-compounds has been developed. The reaction features an unprecedented heterocycle-assisted addition of a diazo-compound to an imine. The obtained diazoesters were efficiently converted into valuable heterocycles as well as β-amino acid derivatives.