Preparation of α-Imino Aldehydes by [1,3]-Rearrangements of O-Alkenyl Oximes
摘要:
The synthesis of alpha-imino aldehydes has been achieved through the thermal [1,3]-rearrangement of O-alkenyl benzophenone oximes. A copper. mediated C-O bond coupling between benzophenone oxime and alkenyl boronic acids provides facile access to the required O-alkenyl oximes and a Horner-Wadsworth-Emmons olefination can be applied to the a-imino aldehyde products to give gamma-imino-alpha,beta-unsaturated esters. The scope of the method is described and mechanistic experiments are discussed.
我们提出了一种高效的钴介导的炔烃和烯烃的硼氢化反应,该反应由 π 酸性和氧化还原活性嘧啶二亚胺 (P Pym DI ) 核心实现。催化循环的入口点是钴二氮络合物而不是氢化钴物质,后者通常在氢元素化反应中假设。化学计量研究表明,氢化钴和二氮络合物都可以由相同的前体在相同的反应条件下生成,唯一的区别在于反应气氛(氩气与氮气)。尽管如此,虽然 P Pym DI 基钴二氮配合物具有高活性(TOF = 1100 h –1 at t 1/2,RT),氢化物类似物在缓慢的反应速率下仅显示适度的转化。在优化的条件下,可以高催化效率获得多种乙烯基和烷基有机硼衍生物。机理研究表明,由于 P Pym DI 核心的 π 酸度增加,优选首先形成 Co-π 配合物,然后是硼烷的氧化加成,这是周转限制步骤。哈米特分析支持了这一系列催化步骤,该分析表明,对于富电子底物,硼氢化反应进行得更快。通过计算、晶体学和光谱手段详细
Enantioselective C(sp3)–C(sp3) cross-coupling of non-activated alkyl electrophiles via nickel hydride catalysis
作者:Srikrishna Bera、Runze Mao、Xile Hu
DOI:10.1038/s41557-020-00576-z
日期:2021.3
attractive candidate compounds in drug discovery. EnantioselectiveC(sp3)–C(sp3) coupling is challenging, especially of alkyl electrophiles without an activating group (aryl, vinyl, carbonyl). Here, we report a strategy based on nickel hydride addition to internal olefins followed by nickel-catalysed alkyl–alkyl coupling. This strategy enables the enantioselective cross-coupling of non-activated alkyl halides
Studies on the Lithiation, Borylation, and 1,2‐Metalate Rearrangement of
<i>O</i>
‐Cycloalkyl 2,4,6‐Triisopropylbenzoates
作者:Rory C. Mykura、Pradip Songara、Eugenia Luc、Jack Rogers、Ellie Stammers、Varinder K. Aggarwal
DOI:10.1002/anie.202101374
日期:2021.5.10
have not. We have studied the use of cyclic TIB esters in lithiation‐borylation reactions and looked at the effect of ringsize (3‐ → 6‐membered rings) on the three key steps of the lithiation‐borylation protocol: deprotonation, borylation and 1,2‐metalate rearrangement. Although all ringssizes could be deprotonated, the cyclohexyl case was impractically slow, and the cyclopentyl example underwent α‐elimination
The present invention provides 5-[5]-[2-cycloa Ikyl ]-6-pyridazin-3-yl ]- IH-pyrimidine-2,4-dione compounds, or pharmaceutically acceptable salts thereof, that inhibit the activity of CD73 and are useful in treating cancer. (Formula (I))
[EN] CRYSTALLINE FORMS OF A CD73 INHIBITOR<br/>[FR] FORMES CRISTALLINES D'UN INHIBITEUR DE CD73
申请人:LILLY CO ELI
公开号:WO2021041319A1
公开(公告)日:2021-03-04
The present invention relates to crystalline forms of 5-[5-[2-isopropylcyclopropyl] -6-methyl-pyridazin-3-yl]-1H-pyrimidine-2,4-dione, and pharmaceutical compositions comprising them, which inhibit the activity of CD73 and are useful for treating cancer.
A Catalytic Dual Isomerization/Allylboration Sequence for the Stereoselective Construction of Congested Secondary Homoallylic Alcohols
作者:Yangbin Liu、Clément Mazet
DOI:10.1021/acs.joc.0c00565
日期:2020.4.17
homoallylboronates into (chiral) aldehydes and allylboronates, respectively. In the same flask, a chiral Brønsted acid is added next to engage the isomerization products into a stereocontrolled allylboration reaction. Structural variations have been performed on both the allylic alcohols and the homoallylboronates. This mild process affords an array of stereochemically congested and complex chiral secondary