Highly satisfactory alkynylation of alkenyl halides via Pd-catalyzed cross-coupling with alkynylzincs and its critical comparison with the sonogashira alkynylation.
[reaction: see text] The Pd-catalyzed alkynylation of various alkenyl halides and triflates with alkynylzincs proceeds well even with alkynyl derivatives containing electron-withdrawing groups. The reaction appears to be highly general. Noteworthy is that the corresponding Sonogashira reactions under various reported conditions are significantly less satisfactory in all cases performed in this study.
Herbert C. Brown Laboratories of Chemistry, Purdue Univesity, West Lafayette, Indiana 47907, USA. negishi@purdue.edu
Ei-Ichi
E
Negishi
Mingxing
M
Qian
Fanxing
F
Zeng
Luigi
L
Anastasia
David
D
Babinski
D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D007202:Indicators and Reagents; D010165:Palladium; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry
D000480:Alkynes; D007202:Indicators and Reagents; D010165:Palladium; D015032:Zinc