Assembly of 2-Substituted Tetrahydroquinolines from -Methylbenzenesulfamides and Dienes, Using a C(sp)-H Activation/Annulation Sequence.

1,2,3,4-Tetrahydroquinolines (THQs) are essential structural cores in many natural products and pharmaceutical drugs. Especially relevant are those presenting substitutions at position 2, yet practical methods for their one-step assembly from acyclic precursors are very scarce. Herein, we present a straightforward approach to assembling these skeletons from -methylanilines using a palladium-catalyzed C(sp)-H activation/formal cycloaddition sequence.

Kinetic Resolution of Allyltriflamides through a Pd-Catalyzed C-H Functionalization with Allenes: Asymmetric Assembly of Tetrahydropyridines.

Enantioenriched, six-membered azacycles are essential structural motifs in many products of pharmaceutical or agrochemical interest. Here we report a simple and practical method for enantioselective assembly of tetrahydropyridines, which is paired to a kinetic resolution of α-branched allyltriflamides. The reaction consists of a formal (4+2) cycloaddition between the allylamine derivatives and allenes and is initiated by a palladium(II)-catalyzed C-H activation process.

Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow.

The first example of photocatalytic trifluoromethoxylation of arenes and heteroarenes under continuous-flow conditions is described. Application of continuous-flow microreactor technology allowed to reduce the residence time up to 16 times in comparison to the batch procedure, while achieving similar or higher yields. In addition, the use of inorganic bases was demonstrated to increase the reaction yield under batch conditions.

Rhodium(III)-Catalyzed Annulation of 2-Alkenyl Anilides with Alkynes through C-H Activation: Direct Access to 2-Substituted Indolines.

A Rh complex featuring an electron-deficient η -cyclopentadienyl ligand catalyzed an unusual annulation between alkynes and 2-alkenyl anilides to form synthetically appealing 2-substituted indolines. Formally, the process can be viewed as an allylic amination with concomitant hydrocarbonation of the alkyne. Mechanistic experiments indicate that this transformation involves an unusual rhodium migration with a concomitant 1,5-H shift.

Palladium-Catalyzed Formal (5 + 2) Annulation between ortho-Alkenylanilides and Allenes.

2-Alkenyltriflylanilides react with allenes upon treatment with catalytic amounts of Pd(OAc) and Cu(II) to give highly valuable 2,3-dihydro-1H-benzo[b]azepines, in good yields, and with very high regio- and diastereoselectivities. Density functional theory (DFT) calculations suggest that the C-H activation of the alkenylanilide involves a classical concerted metalation-deprotonation (CMD) mechanism.