(4-Pentylphenyl)boronic acid → 3,4-Difluoro-4'-pentylbiphenyl-2-carbaldehyde
반응식
Br[C:2]1[CH:9]=[CH:8][C:7]([F:10])=[C:6]([F:11])[C:3]=1[CH:4]=[O:5].[CH2:12]([C:17]1[CH:22]=[CH:21][C:20](B(O)O)=[CH:19][CH:18]=1)[CH2:13][CH2:14][CH2:15][CH3:16]>[Pd]>[F:11][C:6]1[C:7]([F:10])=[CH:8][CH:9]=[C:2]([C:20]2[CH:19]=[CH:18][C:17]([CH2:12][CH2:13][CH2:14][CH2:15][CH3:16])=[CH:22][CH:21]=2)[C:3]=1[CH:4]=[O:5]참가 물질
4
실험 절차
2-bromo-5,6-difluorobenzaldehyde is reacted with 4-pentylphenylboronic acid in the presence of a Pd catalyst to give 3,4-difluoro-4′-pentylbiphenyl-2-carbaldehyde. This compound is reacted with trimethylsulfonium iodide, to give 3,4-difluoro-2-(oxiran-2-yl)-4′-pentyl-biphenyl. Without further purification, this compound is converted into 1,2-difluoro-7-pentylphenanthrene in the presence of BF3 etherate. The raw product is purified by the procedure typical for this type of liquid-crystal materials (cf. DE-A 195 00 768), yielding 1,2-difluoro-7-pentylphenanthrene in the form of colorless crystals. Kumar, J. Org. Chem. 1997, 62, 8535-8539 discloses the coupling of boronic acid compounds with a bromo compound having aldehyde functionality.