通过不对称偕二硼烷的化学选择性氧化获得 MIDA 酰基硼酸盐的模块化和简洁方法:解锁对新型酰基硼的访问†
摘要:
酰基硼酸盐是一类非常有趣且稀有的有机硼酸盐。在温和条件下从容易获得的底物合成这些化合物并获得新型酰基硼一直具有挑战性。我们报告了一种使用不对称偕二硼烷作为关键中间体从末端炔烃/烯烃或乙烯基硼酸酯制备各种 MIDA 酰基硼酸酯的新颖而简洁的途径。该策略的高模块化和温和条件允许轻松获得具有脂肪族、芳香族以及更稀有的杂芳香族、炔基和 α,β-不饱和支架的酰基硼酸盐。据我们所知,这是首个关于双硼化学选择性氧化以及合成 α,β-不饱和酰基硼酸盐的报道。
Superparamagnetic copper ferrite nanoparticles catalyzed aerobic, ligand-Free, regioselective hydroboration of alkynes: Influence of synergistic effect
作者:Balaji Mohan、Kang Hyun Park
DOI:10.1016/j.apcata.2016.03.019
日期:2016.6
We discovered a general and comprehensive approach for the regioselective hydroboration of terminal and internalalkynes to synthesize vinylboronates using inexpensive and magnetically separable copper ferrite nanoparticles at low catalyst loading using Bis(pinacolato)diboron in the absence of ligand and additives, under mild and greener conditions. A diverse range of functional groups was tolerated
and simian immunodeficiency virus. Using facile synthetic approaches that we developed for the synthesis of pyrimido[1,2-c][1,3]benzothiazin-6-imines and related tricyclic derivatives, the parallel structural optimizations of the central 1,3-thiazin-2-imine core, the benzene part, and the cyclicamidinepart of PD 404182 were investigated. Replacement of the 6-6-6 pyrimido[1,2-c][1,3]benzothiazin-6-imine
3,4-二氢-2 H,6 H-嘧啶[1,2- c ] [1,3]苯并噻嗪-6-亚胺(PD 404182)是对多种病毒(包括HCV,HIV和猿猴免疫缺陷病毒)具有活性的杀病毒杂环化合物。使用我们开发的用于合成嘧啶并[1,2- c ] [1,3]苯并噻嗪-6-亚胺和相关三环衍生物的简便合成方法,对中心1,3-噻嗪-2-亚胺的平行结构进行了优化研究了PD 404182的核,苯部分和环am部分。取代6-6-6嘧啶[1,2- c具有5-6-6或6-6-5衍生物的] [1,3]苯并噻嗪-6-亚胺骨架导致抗HIV活性显着下降,并在9-或10-位引入了疏水基团提高了效能。此外,我们证明了PD 404182衍生物在病毒感染的早期发挥了抗HIV的作用。
Catalyst‐Free Enantiospecific Olefination with In Situ Generated Organocerium Species
triorganocerium reagents and their application in catalyst‐free Zweifel olefinations. These unique cerium species were generated through novel exchange reactions of organohalides with n‐Bu3Ce reagents. The adequate electronegativity of cerium allowed for compensating the disadvantages of both usually functional‐group‐sensitive organolithium species and less reactive organomagnesium reagents. Exchange reactions
描述了三有机铈试剂的原位形成及其在无催化剂的Zweifel烯烃中的应用。这些独特的铈物种是通过有机卤化物与n- Bu 3 Ce试剂的新型交换反应生成的。铈具有足够的负电性,可以弥补通常对官能团敏感的有机锂物质和反应性较低的有机镁试剂的缺点。在芳基和烯基溴上进行交换反应,从而实现手性硼频哪醇酯的对映体特异性转化。最终,这些新的有机铈物种参与了可选择性和空间受阻的酮的选择性1,2-加成反应。
Site‐Fixed Hydroboration of Terminal and Internal Alkenes using BX
<sub>3</sub>
/
<sup>
<i>i</i>
</sup>
Pr
<sub>2</sub>
NEt**
作者:Sida Li、Chenyang Hu、Xin Cui、Jiong Zhang、Liu Leo Liu、Lipeng Wu
DOI:10.1002/anie.202111978
日期:2021.12.6
A novel and general method for the hydroboration of alkenes, including arylalkenes, 1,1-disubstitutedalkenes, aliphatic alkenes, and bio-derived alkenes, using BX3 as the boration reagent in the presence of iPr2NEt is reported. The reaction was also applied to the synthesis of linear and branched 1,n-diborylalkanes. The reaction is thought to proceed by a frustrated Lewis pair type single-electron-transfer