Cooperative Catalysis with Coupled Chiral Induction in 1,3-Dipolar Cycloadditions of Azomethine Ylides
作者:Alberto Cayuelas、Olatz Larrañaga、Verónica Selva、Carmen Nájera、Takahiko Akiyama、José M. Sansano、Abel de Cózar、José I. Miranda、Fernando P. Cossío
DOI:10.1002/chem.201801433
日期:2018.6.7
3‐Dipolar cycloadditions (1,3‐DC) between imino esters (as precursors of N‐metallated azomethine ylides) and π‐deficient alkenes are promoted by cooperative asymmetric Lewis acid/Brønsted base catalysis. The components of these catalytic pairs are silver salts derived from enantiopure commercially available BINOL‐based phosphoric acids and Cinchona alkaloids. Chiral phosphoric silver(I) salts promote
不对称路易斯酸/布朗斯台德碱的协同催化作用促进了亚氨基酯(作为N-金属化的甲亚胺烷基化物的前体)与π缺乏的烯烃之间的1,3-偶极环加成(1,3-DC)。这些催化对的成分是衍生自对映纯的市售BINOL基磷酸和金鸡纳生物碱的银盐。手性磷酸银(I)盐促进原位形成的1,3-偶极子的HOMO升高,而质子化的金鸡纳生物碱使双极亲和性菌产生LUMO降低,从而导致1,3-DC的整体加速。用BINOL衍生的磷酸银和氢辛可宁可获得最佳结果。金属和有机催化剂之间的匹配导致对映体过量的增加,优于两种单独组分所达到的对映体过量。