Highly enantio- and chemo-selective 1,4-conjugate addition process of 5H-thiazol-4-ones with maleimides or 1,4-naphthoquinones, and 5H-oxazol-4-ones with maleimides were performed under a dipeptide-based tertiary amine (DP-UAA) catalyst. A series of valuable N,S- and N,O-containing heterocyclic compounds with excellent enantio- and disastereo-selectivities (up to >99% ee, > 20:1 dr) were attained.
Cation Control of Diastereoselectivity in Iridium-Catalyzed Allylic Substitutions. Formation of Enantioenriched Tertiary Alcohols and Thioethers by Allylation of<i>5H</i>-Oxazol-4-ones and<i>5H</i>-Thiazol-4-ones
作者:Wenyong Chen、John F. Hartwig
DOI:10.1021/ja410650e
日期:2014.1.8
corresponding magnesium enolates with high diastereoselectivity. The allylation of substituted 5H-oxazol-4-ones provides rapid access to enantioenriched tertiary α-hydroxy acid derivatives unavailable through Mo-catalyzed allylicsubstitution. The allylation of substituted 5H-thiazol-4-ones provides a novel method to synthesize enantioenriched tertiary thiols and thioethers. The observed cation effect implies
我们报告了由金属环铱配合物催化的取代 5H-恶唑-4-酮和 5H-噻唑-4-酮的高度非对映选择性和对映选择性烯丙基化。通过使用相应的烯醇锌,以高非对映选择性发生取代的 5H-恶唑-4-酮的对映选择性 Ir 催化烯丙基化反应;取代的 5H-噻唑-4-酮的对映选择性 Ir 催化烯丙基化与相应的镁烯醇化物一起发生,具有高非对映选择性。取代的 5H-恶唑-4-酮的烯丙基化可快速获得通过 Mo 催化的烯丙基取代无法获得的对映体富集的叔 α-羟基酸衍生物。取代的 5H-噻唑-4-酮的烯丙基化提供了一种合成富含对映体的叔硫醇和硫醚的新方法。
Remote Stereocontrolled Construction of Vicinal Axially Chiral Tetrasubstituted Allenes and Heteroatom-Functionalized Quaternary Carbon Stereocenters
作者:Pei Zhang、Qiuhong Huang、Yuyu Cheng、Rongshi Li、Pengfei Li、Wenjun Li
DOI:10.1021/acs.orglett.8b03801
日期:2019.1.18
alcohols have been achieved in the presence of chiral phosphoric acids. The remote stereocontrolled activation protocol provides an efficient and facile approach for the construction of vicinal axially chiral tetrasubstituted allenes and heteroatom-functionalized quaternary carbon stereocenters, which expands the synthetic potential of chiral phosphoric acids.
Catalyst-Controlled Diastereodivergent Construction of Vicinal Sulfur-Functionalized Quaternary and Tertiary Stereocenters
作者:Lili Zhang、Huijun Yuan、Wei Lin、Yuyu Cheng、Pengfei Li、Wenjun Li
DOI:10.1021/acs.orglett.8b02088
日期:2018.8.17
with 5H-thiazol-4-ones. The reactions were enabled by two chiral complementary, nonenantiomeric catalysts to furnish a series of adducts possessing vicinal sulfur-functionalized quaternary and tertiarystereocenters in high yields with excellent asymmetric induction. Moreover, o-QMs generated in situ from o-hydroxybenzyl alcohols were also compatible.