Question

please draw a step-wise mechanism for the reacrion between 1-iodo-4-nitrobenze and 2-methyl-3-butyn-2-ol with the reagents Pd(PPh3)2Cl2 , Cul, Et3N.

Answer 1

solution: C = C -он HO c Ec-H 2-methyl-3-butyn-2-01 NOL 1- lodo-4-nitro benzene This is onogashira coupling. It employs a pallasidium catalyst as well as copper co-catalyst orm a carbon-carbond bond between terminal allyne and an aryl or vinyl halide

Mechanismi Pd-precatalyst R-CEC-R R-X hned Ra. RE Tu in pd c -p2 X In pd-cc-R² ©t -c pd cycle Tм , (u Cycle [cu-c=(-2²) -CEC - > И – С – С-Р H-CEC-R² € HX H → Cux 'Bage H- C Ec- R' Ra OA- Oxidative addition, Transmettallation THI - RE- Redudive elimination