Efficient and Practical Oxidative Bromination and Iodination of Arenes and Heteroarenes with DMSO and Hydrogen Halide: A Mild Protocol for Late-Stage Functionalization
efficient and practical system for inexpensive bromination and iodination of arenes as well as heteroarenes by using readily available dimethyl sulfoxide (DMSO) and HX (X = Br, I) reagents is reported. This mild oxidative system demonstrates a versatile protocol for the synthesis of aryl halides. HX (X = Br, I) are employed as halogenating reagents when combined with DMSO which participates in the present
Palladium-Catalyzed Cross-Coupling of Aryl Halides Using Organotitanium Nucleophiles
作者:Hang Wai Lee、Fuk Loi Lam、Chau Ming So、Chak Po Lau、Albert S. C. Chan、Fuk Yee Kwong
DOI:10.1002/anie.200904033
日期:2009.9.21
couple: Catalysts generated from Pd(OAc)2 and indolylphosphine ligands are highly effective in the titanium‐mediated coupling of arylhalides. Catalyst loadings as low as 0.05 mol % Pd can be used. The mild reaction conditions also allow the coupling of aryl sulfonyl chlorides with aryl titanium reagents to generate diaryl sulfones.
Remarkably Effective Phosphanes Simply with a PPh<sub>2</sub>Moiety: Application to Pd-Catalysed Cross-Coupling Reactions for Tetra-<i>ortho</i>-substituted Biaryl Syntheses
作者:Chau Ming So、Wing Kin Chow、Pui Ying Choy、Chak Po Lau、Fuk Yee Kwong
DOI:10.1002/chem.201000723
日期:2010.7.19
Expanding the horizons of ArPPh2: New applications of triarylphosphane ligands are presented. The Pd–L1 and Pd–L2 complexes offer exceptionally high activity in Suzuki–Miyaura cross‐couplings of aryl chlorides. The extremely congested synthesis of tetra‐ortho‐substituted biaryl compounds is achieved for the first time by simply using triarylphosphane ligands.
different substitutions was performed in the presence of alkyl bromide and sodiumhydride in DMSO. Mono-bromination on a wide range of substrates was achieved by selecting proper alkyl bromides and controlling its amount. Further bromination could happen with more active alkyl bromides and additional amount of bromides and sodiumhydride. The yields ranged from moderate to excellent. In addition, reaction