Shun Man Wong

Intramolecular Direct C–H Bond Arylation from Aryl Chlorides: A Transition-Metal-Free Approach for Facile Access of Phenanthridines

A C-H arylation with aryl chloride is made viable through a transition-metal-free approach. In the presence of a simple diol associating with KOt-Bu, various phenanthridine derivatives can be conveniently accessed. In particular, only 10 mol % of simple and inexpensive ethylene glycol is required for this protocol. These results represent the first general examples of aryl chloride/C-H coupling under transition-metal-free conditions.

An efficient palladium–benzimidazolyl phosphine complex for the Suzuki–Miyaura coupling of aryl mesylates: facile ligand synthesis and metal complex characterization

A new class of easily accessible hemilabile benzimidazolyl phosphine ligands has been developed. The ligand skeleton is prepared from commercially available and inexpensive o-phenylenediamine and 2-bromobenzoic acid. With catalyst loading down to 0.5 mol% palladium, excellent catalytic activity towards the Suzuki-Miyaura coupling of aryl mesylates is still observed. This represents the lowest catalyst loading achieved so far for this reaction in general. X-Ray crystallography shows that new ligand L2 is coordinated with Pd in a κ(2)-P,N fashion.

Catalytic Direct C2-Alkenylation of Oxazoles at Parts per Million Levels of Palladium/PhMezole-Phos Complex

General direct C2-alkenylation of oxazoles is reported using alkenyl tosylates at parts per million levels of palladium catalyst. From a series of ligands screened, PhMezole-Phos emerged as the promising ligand candidate to facilitate this reaction. Significantly, the method is scalable and exhibits excellent substrate tolerance. Highly sterically hindered substrates and small vinyl tosylate can be coupled successfully. Moreover, our method enables a rapid diversification of oxazole-based C^N ligands which can be readily derived into new group 9 organometallic compounds.

Recent developments in palladium-catalysed non-directed coupling of (hetero)arene C–H bonds with C–Z (Z = B, Si, Sn, S, N, C, H) bonds in bi(hetero)aryl synthesis

Transition metal-catalysed C–H bond functionalisation is an attractive approach for assembling valuable complex intermediates for the synthesis of pharmaceuticals, natural products, agrochemicals and fine chemicals. Selective functionalisation of one specific C–H site within a complex molecule without the assistance of a directing group is one of the major challenges in organic synthesis. The non-directed functionalisation of C–H bonds is more attractive and straightforward than the directed approach. While several reviews have covered (hetero)aryl (pseudo)halides as coupling partners in non-directed C–H bond functionalisation, this review will complement these existing contributions by focusing on the recent developments involving the employment of organometallic reagents for palladium-catalysed non-directed C–H bond functionalisation of (hetero)arene C–H bonds. Additionally, C–H/C–H bond coupling and other coupling partners will also be fully described.

Preparation of 2-(2-(Dicyclohexylphosphino)phenyl)-1-methyl-1H-indole (CM-phos)

A. 2-(2-Bromophenyl)-1H-indole. An oven-dried 100-mL single-necked round-bottomed flask equipped with a Teflon-coated magnetic stir bar (oval, 25 mm × 15 mm) is charged with 2-bromoacetophenone (2.7 mL, 4.0 g, 20 mmol) (Note 1) and phenylhydrazine (2.4 mL, 2.6 g, 24 mmol) (Note 2) via syringe, and stirring is started. Phosphoric acid (10.0 mL) (Note 3) is added slowly over 1 min, and the mixture is stirred for 50 min (Note 4). NHNH2 H3C O Br H3PO4, PPA N H Br +