Design and Synthesis of Two Aromatic Amines with Dendritic Structure

Abstract

The design and synthesis of two aromatic amines with dendritic structures, i.e. 3,4,5-tribenzyloxyaniline (3,4,5-G(1)-NH2) and 2,5-dibenzyloxyaniline (2,5-G(1)-NH2), were conducted. A coupling reaction of three or two equivalents of benzyl bromide to one equivalent of methyl hydroxybenzoate generated methyl 3,4,5-tribenzyloxybenzoate (3,4,5-G(1)-COOCH3), methyl 2,5-dibenzyloxybenzoate (2,5-G(1)-COOCH3) and 2,6-dibenzyloxybenzoate (2,6-G(1)-COOCH3) in high yields. All G(1)-COOCH3 derivatives were studied by X-ray analysis. The results show that these dendrons have sufficient volume to be used as the fine ligands for certain catalysts. The amide intermediates (benzamide, G(1)-CONH2) were obtained by reaction between ammonia and G(1)-COOCH3. Interestingly, 2,6-dibenzyloxybenzamide (2,6-G(1)-CONH2) can not be prepared in the same condition, which may be due to the overlarge steric block. Sodium hypochlorite was an effective oxidant to generate methyl carbamates G(1)-NHCO2CH3.National Natural Science Foundation of China [20406016]; State Key Laboratory of Physical Chemistry of Solid Surface (Xiamen University

Eight-Step Asymmetric Synthesis of (–)-Berkelic Acid

“…These data are in agreement with those reported previously in the literature. 23 To a solution of methyl 2,6-bis(benzyloxy)benzoate (1.08 g, 3.1 mmol) in HFIP (12 mL) was added NIS (695.2 mg, 3.1 mmol) under air. The reaction mixture was stirred at room temperature over 5 h, then the solvent was removed in vacuum.…”