γ-Carboline synthesis enabled by Rh(iii)-catalysed regioselective C–H annulation

Abstract

A Rh(iii)-catalysed C–H annulation of indolyl oximes with alkynyl silanes was developed, delivering diverse γ-carbolines with unexpected reverse regioselectivity.

Cooperative B–H bond activation: dual site borane activation by redox active κ2-N,S-chelated complexes

“…On the other hand, the 1 H chemical shift at δ = 8.68 ppm corresponds to the C–H proton of the pyridine ligand. 28 …”

“…hand, the 1 H chemical shi at d ¼ 8.68 ppm corresponds to the C-H proton of the pyridine ligand. 28 To have a further understanding of the MLC binding effect in 1,3-N,S-chelated ruthenium complexes, the electrochemistry of fac-3a-b was studied (Fig. S8 †).…”

“…On the other hand, the 1 H chemical shift at δ = 8.68 ppm corresponds to C-H proton of the pyridine ligand. 28 To have further understanding of the MLC binding effect in 1,3-N,S-chelated ruthenium complexes, the electrochemistry of fac-3a-b was carried out (Figure S8). The single quasireverisible redox observed at E 1/2 = 0.59 V (fac-3a) and 0.62 V (fac-3b) assigned to Ru III /Ru II redox couple indicates that the MLC reduces the electrochemical activity of fac-3a-b when compared with trans-mer-1a-b and mer-2a-b species.…”

Noninnocent Behavior of a (3-Imino)indol-2-yl Ligand in Metal Complexes

“…(3-Imino)­indol-2-yl anions can be viewed as derivatives of the 4-alkenyl anions of but-2-en-1-imines. In recent years, some of us (Wang and Zhou) have found that these types of anions are useful C , N -chelating ligands for the preparation of lanthanide complexes that show high catalytic activity in isoprene polymerization. − Noting that transition-metal complexes of (3-imino)­indol-2-yl ligands are scarce, , we then initiated a study on 3d metal complexes of (3-imino)­indol-2-yl ligands. Herein, we wish to report the synthesis, characterization, and redox properties of iron complexes bearing (3-imino)­indol-2-yl ligands, which revealed that this type of C , N -chelating ligand is redox noninnocent.…”

Benzocarbazole Synthesis via Visible-Light-Accelerated Rh(III)-Catalyzed C–H Annulation of Aromatic Amines with Bicyclic Alkenes

“…It provides a powerful tool for the synthesis of bioactive compounds with thermally sensitive substituents. Therefore, to continue our efforts in Rh-catalyzed C–H activation and visible-light-driven organic transformation, herein, we report a visible-light-accelerated Rh­(III)-catalyzed C–H annulation of aromatic amines with bicyclic alkenes. In this protocol, with the cooperation of a Rh catalyst, organic dye, and blue LED irradiation, various valuable bridged oxa or aza tetrahydro benzocarbazoles and benzo­[ b ]­carbazoles were obtained smoothly and efficiently (Scheme f).…”