作者:Wei Xiao、Qian-Qian Yang、Zhi Chen、Qin Ouyang、Wei Du、Ying-Chun Chen
DOI:10.1021/acs.orglett.7b03598
日期:2018.1.5
cyclic 2,4-dienones is adopted to deliver γ′,δ-regioselective [4 + 2] cycloadducts catalyzed by cinchona-derived amines. In addition, a diastereodivergent [4 + 2] cycloaddition reaction is realized with Z-configured 4-alkylideneisoxazol-5(4H)-ones under similar catalytic conditions, even through a three- or four-component cascade process with simple starting materials.
通过使用具有大量α-官能团的活化烯烃,例如α-氰基-α,β-不饱和酮和Meldrum's酸基烯烃,采用了以前未报道的环状2,4-二烯酮的交叉三烯胺途径来传递γ' Cinchona衍生的胺催化的δ区域选择性[4 + 2]环加合物。另外,即使在简单的起始原料的情况下,通过三或四组分级联过程,也可以在相似的催化条件下用Z-构型的4-亚烷基亚异恶唑-5(4 H)-实现非对映异构的[4 + 2]环加成反应。