Cu(II)-Catalyzed <i>ortho</i>-Selective Aminomethylation of Phenols
作者:Jin-Ling Dai、Nan-Qi Shao、Jin Zhang、Run-Ping Jia、Dong-Hui Wang
DOI:10.1021/jacs.7b06785
日期:2017.9.13
A Cu(II)-catalyzed ortho-selective functionalization of free phenols with trifluoroborates to afford Csp2-Csp3 coupling products under mild conditions has been developed. A variety of functional groups on the phenol and the potassium aminomethyltrifluoroborate substrates were found compatible, furnishing the corresponding products in moderate to excellent yields. A single-electron transfer radical
The modified-Mannich reaction: Conversion of arylboronic acids and subsequent coupling with paraformaldehyde and amines toward the one-pot synthesis of Mannich bases and benzoxazines
作者:Juan Liu、Gaoqing Yuan
DOI:10.1016/j.tetlet.2017.02.081
日期:2017.4
A modified Mannichreaction has been developed for the synthesis of Mannichbases and benzoxazines via the oxidative hydroxylation of arylboronic acids and subsequent coupling with paraformaldehyde and amines in one pot. This modified Mannichreaction is easily carried out to afford the target products in good to excellent yields and tolerates a variety of functional groups.
Regioselectivity in Mannich reaction of 4-, 3-, and 2-substituted phenols with typical heterocyclic amines are investigated under reaction conditions developed by Lis. Phenol and 4-alkyl, and 4-chlorophenols in the title reaction predominantly gave the corresponding 2-(aminometllyl)phenols, while 4-methoxyphenol afforded, in addition to the mono(aminomethyl) phenols, a considerable amount of the bis adducts. Peculiarly enough, 3-methylphenol with amines afforded 3-methyl-4-(aminomethyl) phenols whereas 2-methylphenol produced 2-methyl-6-(aminomethyl)phenols.