Reaction of electron-rich arenes with acetyl bromide and aldehydes in the presence of silica gel-supported zinc bromide was carried out in benzene to give selectively the corresponding triarylmethanes or 9,10-diarylanthracenes in high yields depending upon the ratio of an arene and an aldehyde. The mild conditions employed are especially noteworthy.
2-Methoxyalkanoic acids were found to undergo consecutive decarbonylative α,α-diarylation in P2O5-MsOH instead of Friedel-Crafts type arylation on the carbonyl carbon. The influence of the substituents of the arenes and the carboxylic acids in this reaction was elucidated based on the reaction yields. The reaction behavior was found to be primarily governed by the electron-withdrawing/releasing property
发现2-甲氧基链烷酸在P 2 O 5 -MsOH中经历连续的脱羰基α,α-二芳基化,而不是在羰基碳上进行Friedel-Crafts型芳基化。基于反应产率,阐明了芳烃和羧酸的取代基在该反应中的影响。发现反应行为主要受羧酸上α-取代基的吸电子/释放性能以及芳烃的正种接受能力支配。已显示出空间位阻参与确定反应的可行性,并将其作为次要因素。
BF<sub>3</sub>−H<sub>2</sub>O Catalyzed Hydroxyalkylation of Aromatics with Aromatic Aldehydes and Dicarboxaldehydes: Efficient Synthesis of Triarylmethanes, Diarylmethylbenzaldehydes, and Anthracene Derivatives
作者:G. K. Surya Prakash、Chiradeep Panja、Anton Shakhmin、Eric Shah、Thomas Mathew、George A. Olah
DOI:10.1021/jo901668j
日期:2009.11.20
arenes with aromatic aldehydes. This reaction has been extended to aromatic dialdehydes, such as terephthalic dicarboxaldehyde and isoterephthalic dicarboxaldehyde, for the efficient synthesis of diarylmethylbenzaldehydes, which are useful synthons for various organic transformations. Further, successful one step convergent synthesis of various synthetically useful anthracene derivatives from phthalaldehyde
Upon treatment with Fe(CO)5 in an aromatic hydrocarbon solvent aromatic acidchlorides gave an mixture of triarlmethane and tetraarylethane. The reaction may proceed via benzaldehyde and diarylmethanol intermediates. A free radical mechanism is proposed.