Rate Acceleration of the Baylis−Hillman Reaction in Polar Solvents (Water and Formamide). Dominant Role of Hydrogen Bonding, Not Hydrophobic Effects, Is Implicated
作者:Varinder K. Aggarwal、David K. Dean、Andrea Mereu、Richard Williams
DOI:10.1021/jo016073y
日期:2002.1.1
A substantial acceleration of the Baylis-Hillmanreaction between cyclohexenone and benzaldehyde has been observed when the reaction is conducted in water. Several different amine catalysts were tested, and as with reactions conducted in the absence of solvent, 3-hydroxyquinuclidine was found to be the optimum catalyst in terms of rate. The reaction has been extended to other aldehyde electrophiles
Bifunctional Lewis Base Catalyzed Asymmetric <i>N</i>-Allylic Alkylation of 2-Hydroxypyridines
作者:Fei-Ruo Zhang、Fanshu Cao、Kui Liu、Yi-Ping He、Gen Luo、Zhi-Shi Ye
DOI:10.1021/acs.orglett.2c03207
日期:2022.12.2
A chiral Lewis base catalyzed enantioselective N-allylic alkylation of 2-hydroxypyridines and MBH carbonates is documented, affording a convenientaccess to N-alkylated 2-pyridones with up to 99% ee and 99% yield. Experimental and computational studies have revealed that the strong hydrogen bond interaction between the chiral Lewis base catalyst and 2-hydroxypyridines plays a crucial role in this reaction
记录了手性路易斯碱催化的 2-羟基吡啶和 MBH 碳酸酯的对映选择性N-烯丙基烷基化,提供了一种方便地获得N-烷基化 2-吡啶酮的途径,其 ee 高达 99%,产率高达 99%。实验和计算研究表明,手性路易斯碱催化剂与 2-羟基吡啶之间的强氢键相互作用对该反应的反应性、化学选择性和对映选择性起着至关重要的作用。
Asymmetric Synthesis of α‐Methylene‐γ‐Butyrolactones via Tandem Allylboration/Lactonization: a Kinetic Resolution Process
The asymmetric synthesis of α-methylene-γ-butyrolactones via a tandem allylboration/lactonization approach was achieved using a chiral N,N′-dioxide/AlIII complex. The kinetic resolution of the allylboration intermediate via asymmetric lactonization was found to be a key aspect responsible for the success of this transformation. Stereodivergent syntheses and total syntheses of eupomatilones 2, 5 and
使用手性N , N ' -二氧化物/Al III络合物,通过串联烯丙基硼化/内酯化方法实现了 α-亚甲基-γ-丁内酯的不对称合成。发现烯丙基硼化中间体通过不对称内酯化的动力学拆分是该转化成功的关键因素。对Eupomatilones 2、5和6的立体发散合成和全合成证明了其合成实用性。
Electrophilic Warhead-Based Design of Compounds Preventing NLRP3 Inflammasome-Dependent Pyroptosis
Pyroptosis is a caspase-1-dependent pro-inflammatory form of programmed cell death implicated in the pathogenesis of autoinflammatory diseases as well as in disorders characterized by excessive cell death and inflammation. Activation of NLRP3 inflammasome is a key event in the pyroptotic cascade. In this study, we describe the synthesis and chemical tuning of alpha,beta-unsaturated electrophilic warheads toward the development of antipyroptotic compounds. Their pharmacological evaluation and structure-activity relationships are also described. Compound 9 was selected as a model of this series, and it proved to be a reactive Michael acceptor, irreversibly trapping thiol nucleophiles, which prevented both ATP- and nigericin-triggered pyroptosis of human THP-1 cells in a time- and concentration-dependent manner. Moreover, 9 and other structurally related compounds, inhibited caspase-1 and NLRP3 ATPase activities. Our findings can contribute to the development of covalent, multitarget antipyroptotic compounds targeting molecular components of the NLRP3 inflammasome regulatory pathway.
Palladium-catalyzed intramolecular carbonyl allylation via Claisen rearrangement
作者:Yoshiro Masuyama、Yumiko Nimura、Yasuhiko Kurusu
DOI:10.1016/s0040-4039(00)79019-8
日期:1992.10
Palladium-catalyzed intramolecular carbonyl allylation with SnCl2 by 5-substituted 4-methylene-5-(2-tetrahydropranyloxy)pentanals, prepared by Claisen rearrangement of 2-[1-(2-tetrahydropyranyloxy)alkyl]allylvinylethers, occurred radioselectively at ambienttemperature in DMI/H2O to give 2-substituted 3-methylenecyclopentanols in good yields.
通过2- [1-(2-(4-四氢吡喃氧基)烷基]烯丙基乙烯基醚的克莱森重排制备的5-取代的4-亚甲基-5-(2-四氢戊氧基)戊醛与SnCl 2进行钯催化的分子内羰基烯丙基化反应,于在DMI / H 2 O中的室温下以良好的产率得到2-取代的3-亚甲基环戊醇。