A New Step Towards Solid Base Catalysis: Azidoproazaphosphatranes Immobilized in Nanopores of Mesoporous Silica
作者:Pascal Dimitrov Raytchev、Anissa Bendjeriou、Jean-Pierre Dutasta、Alexandre Martinez、Véronique Dufaud
DOI:10.1002/adsc.201100270
日期:2011.8
proazaphosphatranes, known as Verkade’s superbases, were prepared for the first time by covalent immobilization onto SBA-15 silica. In order to introduce the tether to the surface, three siloxane-containing azido derivatives of the proazaphosphatranes were first synthesized (2a–c) which after post-synthetic grafting onto silica support led to the formation of hybrid materials of different basicity and steric properties
通过共价键固定在SBA-15二氧化硅上,首次制备了由原氮杂磷杂环戊烷衍生而来的非均相碱性催化剂,即Verkade的超强碱。为了将系链引入表面,首先合成了三氮杂原磷烷的含硅氧烷叠氮基衍生物(2a–c),将其合成后接枝到二氧化硅载体上后,形成了具有不同碱性和空间特性的杂化材料,2a–c @ SBA-15。后者使用多种分子和固态技术进行了充分表征,以确定它们的结构和质地特性。然后,在蒽酮和3-羟基-2-吡喃酮与两种缺电子的亲二烯体的Diels–Alder反应中评估了这些新型的固体碱催化剂,N-甲基马来酰亚胺和富马酸二甲酯。通常,取决于催化剂的种类,可以获得高活性和选择性,其性能以甲氧基苄基>新戊基>甲基叠氮基磷杂环戊烯的顺序降低。研究了最好的催化剂,即甲氧基苄基衍生物2c @ SBA-15的催化剂循环利用,结果表明该催化剂可以重复使用多达3个循环,然后才能检测到任何活性降低。