Substituted Functional Olefins Through Lateral Sequential Lithiation/Silylation/Condensation of Tertiary Aromatic Amides: A Ligand for Phosphane-Free Palladium-Catalyzed Suzuki Coupling Reactions

• Published in: European Journal of Organic Chemistry Vol. 2012; no. 2; pp. 290 - 297
• Main Authors: Xu, Li-Wen, Chen, Xi-Huai, Shen, Hao, Deng, Yuan, Jiang, Jian-Xiong, Jiang, Kezhi, Lai, Guo-Qiao, Sheng, Chun-Qi
• Format: Book Review Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.01.2012; WILEY‐VCH Verlag; Wiley; Wiley-VCH
• Subjects: Chemistry; Chemistry, Organic; Cross-coupling; Exact sciences and technology; Lithiation; Noncondensed benzenic compounds; Olefination; Organic chemistry; Palladium; Physical Sciences; Preparations and properties; Science & Technology; Silylation; ASYMMETRIC-SYNTHESIS; ENANTIOSELECTIVE SYNTHESIS; C-O; Olefination; Silylation; ATROPISOMERIC AMIDES; Palladium; Cross-coupling; BENZAMIDES; Lithiation; BONDS; ARYL; EFFICIENT; CONFORMATIONAL PREFERENCE; Ligand; Fluorescence; Palladium complex; Molecular interaction; NMR spectrometry; Oxygen heterocycle; Cross reaction; Aromatic compound; Palladium II Acetate; Solvent; Cesium carbonate; Catalytic reaction; Condensation reaction; Dioxane derivatives; Transition metal; Chemical coupling; Suzuki coupling; Olefin; Carboxamide; Benzenic compound; Ethylenic compound; Ultraviolet visible spectrometry
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201101284

An unprecedented lateral sequential lithiation/silylation/condensation of tertiary aromatic amides has been developed that provides an efficient method to build up functional olefins in good yields. In addition, we have established an efficient and simple method that involves UV/Vis, fluorescence, and NMR analyses, to detect the interaction between transition‐metal salts and functional olefins containing tertiary amides. This has enabled a highly efficient palladium‐catalyzed Suzuki coupling reaction in the presence of tertiary aromatic amide‐derived olefin ligands to be developed. The best results were obtained by employing 2 mol‐% Pd(OAc)2, 2 equiv. Cs2CO3, a reaction temperature of 80 °C, dioxane as the solvent, and phosphane‐free olefin 2d as ligand. A new type of olefin was prepared by an unprecedented lateral sequential lithiation/silylation/condensation of tertiary aromatic amides in good yield. The resulting functional olefin, containing an amide moiety, could act as an efficient ligand in phosphane‐free palladium‐catalyzed Suzuki cross‐coupling reactions.