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。
Stereodivergent Construction of 1,3‐Chiral Centers via Tandem Asymmetric Conjugate Addition and Allylic Substitution Reaction
作者:Jia‐Hao Xie、Yi‐Ming Hou、Zuolijun Feng、Shu‐Li You
DOI:10.1002/anie.202216396
日期:2023.3
cyclohexanones bearing multi-continuous stereocenters by combining copper-catalyzed asymmetric conjugate addition of dialkylzinc reagents to cyclic enones with iridium-catalyzed asymmetric allylicsubstitution reaction. Good to excellent yields, diastereoselectivity and enantioselectivity can be obtained. The current reaction can achieve the stereodivergent construction of nonadjacent stereocenters.
alkylation of Schiff base activated amino acids and small peptides via a Pd/Cu dual catalysis. A range of noncoded α,α-dialkyl α-aminoacids were easily synthesized in high yields and with excellent enantioselectivities (up to >99% ee). Furthermore, a direct and highly stereoselective synthesis of small peptides with enantiopure α-alkyl or α,α-dialkyl α-aminoacids residues incorporated at specific sites