Utilization of sulfur function in directed catalytic C-H transformation: Site-selective substitution on indole and naphthalene skeletons

Sulfur-containing functional groups, among various coordinating functions, have recently attracted attention as useful directing groups for the direct catalytic C-H transformation of aromatic and heteroaromatic compounds. Herein we briefly summarize our recent work on the site-selective substitution on indole and naphthalene skeletons using thioether directing groups under either Cp*Rh(III) or Cp*Ir(III) catalysis. The thioether groups can readily be removed and transformed to other functional groups. The reactions developed appear to be of importance in pharmaceutical and materials chemistry.</p

Rhodium-Catalyzed C6-Selective C–H Borylation of 2‑Pyridones

A pyridine-directed, rhodium-catalyzed C6-selective C–H borylation of 2-pyridones with bis­(pinacolato)­diboron (pinB–Bpin) has been developed. The reaction proceeds smoothly under relatively mild conditions, and the corresponding C6-borylated 2-pyridones are obtained with perfect site selectivity. Subsequent palladium-catalyzed Suzuki–Miyaura cross-coupling is followed by the removal of the pyridine directing group to form the C6-arylated NH-pyridone in an acceptable overall yield

Copper-Mediated Oxidative Coupling of Benzamides with Maleimides via Directed C–H Cleavage

A Cu­(OAc)₂/Cy₂NMe-mediated oxidative direct coupling of benzamides with maleimides has been developed. The aromatic C–H alkenylation with the aid of an 8-aminoquinoline-based bidentate directing group is followed by an intramolecular aza-Michael-type addition to form the isoindolone-incorporated spirosuccinimides, which are of potent interest in medicinal chemistry

Rhodium-Catalyzed C6-Selective C–H Borylation of 2‑Pyridones

A pyridine-directed, rhodium-catalyzed C6-selective C–H borylation of 2-pyridones with bis­(pinacolato)­diboron (pinB–Bpin) has been developed. The reaction proceeds smoothly under relatively mild conditions, and the corresponding C6-borylated 2-pyridones are obtained with perfect site selectivity. Subsequent palladium-catalyzed Suzuki–Miyaura cross-coupling is followed by the removal of the pyridine directing group to form the C6-arylated NH-pyridone in an acceptable overall yield

Copper-Mediated Oxidative Coupling of Benzamides with Maleimides via Directed C–H Cleavage

A Cu­(OAc)₂/Cy₂NMe-mediated oxidative direct coupling of benzamides with maleimides has been developed. The aromatic C–H alkenylation with the aid of an 8-aminoquinoline-based bidentate directing group is followed by an intramolecular aza-Michael-type addition to form the isoindolone-incorporated spirosuccinimides, which are of potent interest in medicinal chemistry

Rhodium-Catalyzed C6-Selective C–H Borylation of 2‑Pyridones

A pyridine-directed, rhodium-catalyzed C6-selective C–H borylation of 2-pyridones with bis­(pinacolato)­diboron (pinB–Bpin) has been developed. The reaction proceeds smoothly under relatively mild conditions, and the corresponding C6-borylated 2-pyridones are obtained with perfect site selectivity. Subsequent palladium-catalyzed Suzuki–Miyaura cross-coupling is followed by the removal of the pyridine directing group to form the C6-arylated NH-pyridone in an acceptable overall yield

Rhodium-Catalyzed C6-Selective C–H Borylation of 2‑Pyridones

A pyridine-directed, rhodium-catalyzed C6-selective C–H borylation of 2-pyridones with bis­(pinacolato)­diboron (pinB–Bpin) has been developed. The reaction proceeds smoothly under relatively mild conditions, and the corresponding C6-borylated 2-pyridones are obtained with perfect site selectivity. Subsequent palladium-catalyzed Suzuki–Miyaura cross-coupling is followed by the removal of the pyridine directing group to form the C6-arylated NH-pyridone in an acceptable overall yield

Asymmetric Synthesis of α‑Aminoboronic Acid Derivatives by Copper-Catalyzed Enantioselective Hydroamination

A copper-catalyzed regio- and enantio­selective hydroamination of alkenyl dan boronates (dan =1,8-diaminonaphthyl) with hydrosilanes and hydroxylamines proceeds to deliver the chiral α-aminoboronic acids in good yields with high enantiomeric ratios. The key to success is the introduction of an umpolung, electrophilic amination strategy. The copper catalysis can provide an unprecedented catalytic asymmetric approach to alkyl-substituted chiral α-aminoboronic acid derivatives of great potential in the fields of organic synthesis and medicinal chemistry