Using indium (III) triflate as a mild Lewis acid catalyst, the Friedel Crafts alkylation of o-hydroxy bisbenzylic alcohols with aromatic/heteroaromatic arenes under solvent free conditions was achieved to give the corresponding unsymmetrical triarylmethanes in high yields (up to 80% yield). Calculation of the different green metrics for the above reaction revealed it to have high atom economy (94–96%), high reaction mass efficiency (66–77%) and high carbon efficiency (70–80%). The Lewis acid was found to be air and moisture tolerant. The protocol was found to be operationally simple and can be carried out in an “open-flask” leaving behind water as the sole by product. Gratifyingly the Lewis acid catalyst could be recycled and reused up to 5 catalytic cycles without compromising much on the yield thus further highlighting the importance of the protocol.

使用三氟甲磺酸铟（III）作为温和的路易斯酸催化剂，将Friedel Crafts烷基化为邻在无溶剂条件下获得了具有芳族/杂芳族芳烃的-羟基双苄基醇，以高收率（最高收率80％）得到了相应的不对称三芳基甲烷。对上述反应的不同绿色度量的计算表明，它具有较高的原子经济性（94-96％），较高的反应质量效率（66-77％）和较高的碳效率（70-80％）。发现路易斯酸是耐空气和潮湿的。发现该协议操作简单，可以在“开放式烧瓶”中进行，而留下的水是唯一的副产品。令人欣慰的是，路易斯酸催化剂可以循环使用并重复使用多达5个催化循环，而不会影响收率，因此进一步突出了该方案的重要性。