Enantioselective Iridium-Catalyzed Allylic Alkylation of Racemic Branched Alkyl-Substituted Allylic Acetates with Malonates
作者:Tian-Yuan Zhang、Yi Deng、Kun Wei、Yu-Rong Yang
DOI:10.1021/acs.orglett.0c04309
日期:2021.2.5
The regio- and enantioselective allylic substitution of branched alkyl-substituted allylic acetates employing malonates has been achieved through a process that calls for Krische’s π-allyliridium C,O-benzoate catalyst. The protocol reported herein can be applied to a diverse set of branched alkyl substrates that are generally not well tolerated in the other two types of Ir-catalyzed allylation.
Enantioselective Iridium-Catalyzed Phthalide Formation through Internal Redox Allylation of Phthalaldehydes
作者:James M. Cabrera、Johannes Tauber、Michael J. Krische
DOI:10.1002/anie.201712015
日期:2018.1.26
An inside job: Enantioselective phthalide synthesis was achieved through internal redox allylation of o‐phthalaldehydes. Oxidative esterification is balanced by reductive carbonyl addition to achieve an overall redox‐neutral process. This method enabled formal syntheses of ent‐spirolaxine methyl ether and CJ‐12,954.
Ethanol: Unlocking an Abundant Renewable C
<sub>2</sub>
‐Feedstock for Catalytic Enantioselective C−C Coupling
作者:Cole C. Meyer、Nicholas P. Stafford、Melinda J. Cheng、Michael J. Krische
DOI:10.1002/anie.202102694
日期:2021.5.3
production at >85 million tons/year, ethanol is the world's largest‐volume renewable small molecule carbon source, yet its use as a C2‐feedstock in enantioselective C−C coupling is unknown. Here, the first catalytic enantioselective C−C couplings of ethanol are demonstrated in reactions with structurally complex, nitrogen‐rich allylic acetates incorporating the top 10 N‐heterocycles found in FDA‐approved
乙醇的年产量超过 8500 万吨/年,是世界上产量最大的可再生小分子碳源,但其在对映选择性 C−C 偶联中作为 C 2原料的用途尚不清楚。在这里,乙醇的第一个催化对映选择性 C−C 偶联在与结构复杂、富含氮的烯丙乙酸酯的反应中得到证实,其中含有 FDA 批准的药物中发现的前 10 个氮杂环。
Ni-Catalyzed Asymmetric Allylation of Secondary Phosphine Oxides
A nickel catalyzed asymmetric allylation of secondary phosphineoxides (SPO) for the synthesis of tertiary phosphineoxides (TPO) was realized with high enantioselectivity. The dynamic kinetic resolution of SPO was accomplished in the presence of nickel complex. By elucidating the absolute configurations of the reacted SPO starting material and the TPO product, we confirmed that the allylation reaction
Selection between Diastereomeric Kinetic vs Thermodynamic Carbonyl Binding Modes Enables Enantioselective Iridium-Catalyzed <i>anti</i>-(α-Aryl)allylation of Aqueous Fluoral Hydrate and Difluoroacetaldehyde Ethyl Hemiacetal
作者:James M. Cabrera、Johannes Tauber、Wandi Zhang、Ming Xiang、Michael J. Krische
DOI:10.1021/jacs.8b05725
日期:2018.8.1
increasing carbonyl electrophilicity in 2-propanol-mediated reductive couplings of aldehydes with branched aryl-substituted allylic acetates to form products of carbonyl anti-(α-aryl)allylation. This unusual phenomenon is caused by aldehyde coordination to diastereomeric kinetic vs thermodynamic carbonyl binding sites that deliver enantiomeric products. Exploiting this effect, anti-diastereo- and enantioselective