Chiral Bidentate Phosphoramidite-Pd Catalyzed Asymmetric Decarboxylative Dipolar Cycloaddition for Multistereogenic Tetrahydrofurans with Cyclic <i>N</i>-Sulfonyl Ketimine Moieties
作者:Hao-Peng Lv、Xiao-Peng Yang、Bai-Lin Wang、Hao-Di Yang、Xing-Wang Wang、Zheng Wang
DOI:10.1021/acs.orglett.1c01411
日期:2021.6.18
An asymmetric [3 + 2] cycloaddition of vinyl ethylenecarbonates (VECs) and (E)-3-arylvinyl substituted benzo[d] isothiazole 1,1-dioxides has been developed using the Pd complex of a bidentate phosphoramidite (Me-BIPAM) as the catalyst, providing a wide variety of chiral multistereogenic vinyltetrahydrofurans in good yields with excellent diastereo- and enantioselectivities (up to >20:1 dr, 99% ee)
tertiary C-O bond via asymmetric allylicsubstitution of racemic vinylethylene carbonates with water and alcohols has been developed. Under the cooperative catalysis system of an in situ generated chiral palladium complex and boron reagent in mild conditions, the process allowed rapid access to valuable tertiary alcohols and ethers in high yields with complete regioselectivities and high enantioselectivities
已经开发了一种通过外消旋乙烯基碳酸亚乙酯与水和醇的不对称烯丙基取代对映选择性构建叔 CO 键的有效方法。在温和条件下原位生成的手性钯配合物和硼试剂的协同催化系统下,该过程允许以高产率快速获得有价值的叔醇和醚,具有完整的区域选择性和高对映选择性。该协议代表了与作为氧供体的水直接对映选择性形成三级 CO 键的第一个例子。该过程的合成效用已通过将产品加工成生物相关制剂的关键中间体来证明,
Direct Synthesis of Substituted (
<i>Z</i>
)‐Allylic Sulfones by Palladium‐Catalyzed Sulfonylation of Vinylethylene Carbonates with Sodium Sulfinates
A palladium‐catalyzed highly stereoselective sulfonylation of vinylethylene carbonates for the precise synthesis of structurally diverse (Z)‐allylic sulfones was achieved with excellent regioselectivity and stereoselectivity (Z/E ratio, up to 99 : 1). This protocol used inexpensive sodium sulfinates as sulfonyl sources to construct valuable (Z)‐allylic sulfones in good to excellent yields. The controlling
Copper-Mediated S<sub>N</sub>2′ Allyl–Alkyl and Allyl–Boryl Couplings of Vinyl Cyclic Carbonates
作者:Núria Miralles、José Enrique Gómez、Arjan W. Kleij、Elena Fernández
DOI:10.1021/acs.orglett.7b02947
日期:2017.11.17
for the copper-catalyzed borylmethylation and borylation of vinyl cyclic carbonates through an SN2′ mechanism is reported. These singular reactions involve selective SN2′ allylic substitutions with concomitant ring opening of the cyclic carbonate and with extrusion of CO2 and formation of a useful hydroxyl functionality in a single step. The stereoselectivity of the homoallylic borylation and allylic
报道了一种通过S N 2'机理进行铜催化的乙烯基环状碳酸酯的硼烷基甲基化和硼化的方法。这些奇异反应包括选择性的S N 2'烯丙基取代,伴随有环状碳酸酯的开环,以及CO 2的挤出和在单个步骤中形成有用的羟基官能团。可以控制均烯丙基硼化和烯丙基硼化过程的立体选择性,并且合成上有用的不饱和(E)-戊-2-烯-1,5-二醇和(E)-丁-2-烯-1,4-二醇是访问。
Palladium-Catalyzed (<i>Z</i>)-Selective Allylation of Nitroalkanes: Access to Highly Functionalized Homoallylic Scaffolds
作者:Àlex Cristòfol、Eduardo C. Escudero-Adán、Arjan W. Kleij
DOI:10.1021/acs.joc.8b01372
日期:2018.9.7
presence of vinyl-substituted cyclic carbonates, providing a wide variety of functionalized homoallylated compounds with exquisite stereocontrol. This Pd-mediated procedure features operational simplicity, versatile substrate combinations, and also allows for the sequential introduction of different allyl groups in the nitroalkane scaffolds with high levels of stereocontrol through the intermediacy of a (Z)-configured