Synthesis of novel cinchona-amino acid hybrid organocatalysts for asymmetric catalysis
作者:Pedro Barrulas、Maurizio Benaglia、Anthony J. Burke
DOI:10.1016/j.tetasy.2014.05.003
日期:2014.6
Three novel subclasses of cinchonidine derivatives coupled to diverse amino acids were prepared in very good overall yield and tested in a benchmark organocatalytic aldol reaction, between acetone and aromatic aldehydes. These subclasses are a family of amino acid-cinchonidine (subclass A), N-formamides-cinchonidine (subclass B) and dipeptide-cinchonidine (subclass C) hybrids. Our main goal, besides
以非常好的总收率制备了三类新的辛可尼定衍生物与不同的氨基酸偶联,并在丙酮和芳族醛之间进行了基准有机催化醛醇缩合反应,并进行了测试。这些子类是氨基酸辛可尼定(子类A),家族Ñ-formamides辛可尼定(子类B)和二肽辛可尼定(子类C)杂交。我们的主要目标,除了获得很好的收益和对映选择性,是了解氨基酸侧链残基上的不对称羟醛缩合反应的对映选择性的影响。不同的氨基酸系留辛可尼丁杂种进行了比较,它们的催化行为进行评价,从而允许在一种情况下要实现良好的对映选择性,92%ee的。用这些配体筛选了其他反应,例如Biginelli,迈克尔加成反应和酮亚胺氢化硅烷化反应,但结果不太成功。