Noncryogenic I/Br-Mg exchange of aromatic halides bearing sensitive functional groups using i-PrMgCl-bis[2-(N,N-dimethylamino)ethyl] ether complexes.
[reaction: see text] Iodo- and bromoaromatics bearing sensitive carboxylic ester and cyano groups underwent a selective halide-magnesium exchange with isopropylmagnesium chloride at ambient temperature in the presence of bis[2-(N,N-dimethylamino)ethyl] ether to afford the corresponding Grignard reagents. The newly formed reactive Grignard reagents were allowed to react with electrophiles such as trimethylborate to afford arylboronic acids in good to excellent yields.
Wang
Xiao-Jun
XJ
Department of Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut 06877, USA. xwang@rdg.boehringer-ingelheim.com
Sun
Xiufeng
X
Zhang
Li
L
Xu
Yibo
Y
Krishnamurthy
Dhileepkumar
D
Senanayake
Chris H
CH