描述了一种温和且操作简单的铜催化乙烯基有氧氧化 β,γ-和 α,β-不饱和酯。该方法具有收率好、底物范围广、化学选择性和区域选择性好、官能团耐受性好等特点。该方法还能够氧化β,γ-和α,β-不饱和醛、酮、酰胺、腈和砜。此外,本催化体系适用于双乙烯基和三乙烯基氧化。发现四甲基胍 (TMG) 作为碱的作用至关重要,但我们也推测它可以作为三氟甲磺酸铜 (II) 的配体来生产活性铜 (II) 催化剂。进行的机械实验表明,通过烯丙基铜 (II) 物质存在一个合理的反应途径。最后,
描述了一种温和且操作简单的铜催化乙烯基有氧氧化 β,γ-和 α,β-不饱和酯。该方法具有收率好、底物范围广、化学选择性和区域选择性好、官能团耐受性好等特点。该方法还能够氧化β,γ-和α,β-不饱和醛、酮、酰胺、腈和砜。此外,本催化体系适用于双乙烯基和三乙烯基氧化。发现四甲基胍 (TMG) 作为碱的作用至关重要,但我们也推测它可以作为三氟甲磺酸铜 (II) 的配体来生产活性铜 (II) 催化剂。进行的机械实验表明,通过烯丙基铜 (II) 物质存在一个合理的反应途径。最后,
Effective construction of quaternary stereocenters by highly enantioselective α-amination of branched aldehydes
作者:Ji-Ya Fu、Xiao-Ying Xu、Yan-Chun Li、Qing-Chun Huang、Li-Xin Wang
DOI:10.1039/c0ob00406e
日期:——
A highly efficient enantioselectiveα-amination of branchedaldehydes with azadicarboxylates promoted by chiral proline-derived amide thiourea bifunctional catalysts was developed for the first time, affording the adducts bearing quaternary stereogenic centers with excellent yields (up to 99%) and enantioselectivities (up to 97% ee).
Asymmetric α-Allylation of Aldehydes with Alkynes by Integrating Chiral Hydridopalladium and Enamine Catalysis
作者:Yong-Liang Su、Lu-Lu Li、Xiao-Le Zhou、Zhen-Yao Dai、Pu-Sheng Wang、Liu-Zhu Gong
DOI:10.1021/acs.orglett.8b00740
日期:2018.4.20
A palladium-catalyzed asymmetric α-allylation of aldehydes with alkynes has been established by integrating the catalysis of enamine and chiral hydridopalladium complex that is reversibly formed from the oxidative addition of Pd(0) to chiral phosphoric acid. The ternary catalyst system, consisting of an achiral palladium complex, a primary amine, and a chiral phosphoric acid allows the reaction to
Boron Trifluoride Etherate-Controlled Reactions of Methyl Enol Ethers: Selective Synthesis of Dihydrofuro[3,2-c]chromenone and Furo[3,2-c]chromenone Derivatives
作者:Faiz Ahmed Khan、Sarwat Asma Ziya Ahmad
DOI:10.1055/a-1912-3884
日期:——
A facile one-step synthetic approach to dihydrofuro-[3,2-c]chromenones and furo[3,2-c]chromenones by the reaction of methyl enol ethers with 4-hydroxycoumarins under metal-free conditions is presented. Dihydrofuro[3,2-c]chromenones and furo[3,2-c]-chromenones were selectively obtained by controlling the stoichiometry of boron trifluoride diethyl etherate. An unexpected aryl-group migration followed
提出了一种在无金属条件下通过甲基烯醇醚与 4-羟基香豆素反应来简便地一步合成二氢呋喃-[3,2- c ]色酮和呋喃[3,2 - c ]色酮的方法。通过控制三氟化硼乙醚合物的化学计量,选择性地得到二氢呋喃[3,2- c ]色酮和呋喃[3,2- c ]-色酮。据报道,芳基迁移后呋喃部分芳构化,导致各种呋喃[3,2- c ]色烯酮衍生物的收率良好。