Stereoselective palladium-catalyzed cross-coupling of (2-amido-1-phenylpropyl)zinc compounds with aryl bromides

• Published in: Chemical research in Chinese universities Vol. 29; no. 4; pp. 678 - 681
• Main Authors: Tang, Shi, Zhou, Dong, Li, Shu-hua, Wang, Nai-xing
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2013; College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, P.R.China; Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R.China%College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, P.R.China%Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R.China
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Inorganic Chemistry; Organic Chemistry; Physical Chemistry; Negishi coupling; Palladium; Benzylic zinc; 2-Arylphenylethylamine; Stereoselective
• ISSN: 1005-9040
• DOI: 10.1007/s40242-013-3057-z

A controllable diastereoselective C( sp 2 )-C( sp 3 ) Negishi coupling reaction of secondary benzylic zinc reagents with aryl bromides to form medicinally important 2-arylphenylethylamines was demonstrated. In the presence of Pd(OAc) 2 and 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl(S-phos), open-chain(2-amido-1-phenylethyl)zinc reagent bearing a β -NHAc or NHCHO group undergoes coupling reaction to give syn -1-arylphenylethylamine mainly, whereas the zinc reagent bearing a sterically hindered β -amido group, for example NHCOC(CH 3 ) 2 OTBS undergoes the coupling reaction to yield anti -1-arylphenylethylamines with a configuration inversion. In addition, a working mechanism for the stereoselective Negishi cross-coupling was also proposed.