ChemInform Abstract: Regioselective Mannich Reaction of Phenols under High Pressure Using Dichloromethane as C1 Unit.

Abstract

Monovalent phenols Q 0180Regioselective Mannich Reaction of Phenols under High Pressure Using Dichloromethane as C1 Unit. -In contrast to the conventional Mannich reaction the reaction of phenols (I) with cyclic amines (III) is characterized by regiospecific 2-aminomethylation to give the mono(aminomethyl) analogues (IV). The activated methoxy-and chlorophenols (V) afford the mono adducts (VI) together with a considerable amount of the bis adducts (VII), being in agreement with the known reactivity-selectivity principle. The para-regioselectivity in the reaction of 3-methylphenol (VIII) with amines (III) is ascribed to the +M effect of the OH group.Very intriguingly, 2-methylphenol (X) affords the 6-substituted phenol (XI). -(MATSUMOTO*, K.; JOHO, K.; MIMORI, S.; IIDA, H.; HAMANA, H.; KAKEHI, A.; Heterocycles 76 (2008) 2, 1061-1067; Elm Inst. Sci., Otsu 520, Japan; Eng.) -H. Hoennerscheid