An Axially Chiral Styrene-Phosphine Ligand for Pd-Catalyzed Asymmetric N-Alkylation of Indoles.

An efficient palladium-catalyzed enantioselective direct N-alkylation of indoles using a novel type of axially chiral styrene-phosphine ligand SJTU-PHOS-1 was developed. This reaction demonstrated good functional group compatibility and a wide range scope of substrates in mild conditions. Moreover, the DFT calculations expounded the coordination mode of the metal catalyst and the axially chiral styrene-phosphine ligand in the enantioselectivity control.

Cu-Mediated Stereoselective [4+2] Annulation between N-Hydroxybenzimidoyl Cyanide and Norbornene.

A Cu-mediated stereoselective [4+2] annulation between N-hydroxybenzimidoyl cyanides and norbornene (NBE) has been developed for the synthesis of 4 H-1,2-oxazin-4-ones. The reaction proceeds through sequentially forming C-O/C-C bonds. The advantage of this reaction includes high stereoselectivity, excellent yields, as well as simple and mild reaction conditions. A total of 26 examples are presented along with some control experiments.

Palladium-catalyzed oxidative coupling of arylboronic acid with isocyanide to form aromatic carboxylic acids.

A valuable palladium-catalyzed oxidative coupling of aryl- and alkenyl borides with isocyanide for the synthesis of corresponding carboxylic acids has been developed. With wide substrate scopes and good functional group tolerance, this reaction offers corresponding carboxylic acids in moderate to excellent yields.

Palladium-catalyzed carbonylative synthesis of isocoumarins and phthalides by using phenyl formate as a carbon monoxide source.

A simple and efficient palladium-catalyzed intramolecular carbonylative synthesis of isocoumarins and phthalides from the easily available starting materials by employing phenyl formate as a CO surrogate has been achieved. The approach affords target compounds in good to excellent yields with the advantages of lower toxicity, milder conditions, easy operation and wide functional group tolerance.

Palladium-Catalyzed Synthesis of α-Iminonitriles from Aryl Halides via Isocyanide Double Insertion Reaction.

An efficient one-pot synthesis of α-iminonitriles from readily available aryl halides via palladium-catalyzed double isocyanide insertion and elimination has been developed, without using various hypertoxic cyanides and excess oxidants. Furthermore, the utility of this reaction was demonstrated by the rapid total synthesis of quinoxaline and the reaction of functional groups exchanged with aryl halides.

Palladium-Catalyzed Carbonylative Annulation Reactions Using Aryl Formate as a CO Source: Synthesis of 2-Substituted Indene-1,3(2H)-dione Derivatives.

An efficient synthesis of 2-substituted indene-1,3(2H)-diones from stable and readily available 1-(2-halophenyl)-1,3-diones by employing phenyl formate as a CO source has been developed. The reaction occurred via palladium-catalyzed intramolecular carbonylative annulation using K3PO4 as a base and DMSO as a solvent at 95 °C. In this protocol, the reaction showed a broad substrate scope with good to excellent yields.

Palladium-catalyzed one-pot synthesis of diazoles via tert-butyl isocyanide insertion.

An efficient one-pot palladium-catalyzed reaction for the synthesis of diazoles from readily available hydrazides and aryl halide via isocyanide insertion/cyclization sequence has been developed. This methodology efficiently constructs diazoles in good to excellent yields with the advantages of wide functional group tolerance and operational simplicity.