A Method for the Deprotection of Alkylpinacolyl Boronate Esters
摘要:
A two-step procedure for deprotection of alkylpinacolyl boronate esters via transesterification with diethanolamine followed by hydrolysis was successfully developed with the advantages of tolerance to various functional groups, short reaction time, and ease of product isolation.
报道了烯烃和炔烃的光催化硼氢化反应。使用新设计的铜光催化剂和 B 2 Pin 2可以形成硼基自由基,该自由基可用于大量烯烃和炔烃的硼氢化反应。硼氢化产物以高产率分离,在温和条件下具有优异的非对映选择性和高官能团耐受性。硼氢化反应是在连续流动条件下开发的,以证明其合成效用。研究了反应机理,并提出了原位形成的硼酸盐和处于激发态的铜光催化剂之间的氧化反应,以形成硼基自由基。
perform as an efficient heterogeneous catalyst for the synthesis of useful organoboron compounds. Desired β-borylation products were all obtained in good to excellent yields under mild conditions. This catalyst could be recovered easily and still work effectively in six runs. Notably, asymmetric synthesis of organoboron compounds was accomplished by applying a chiral phosphine ligand. This newly developed
Catalyst-free chemoselective conjugate addition and reduction of α,β-unsaturated carbonyl compounds <i>via</i> a controllable boration/protodeboronation cascade pathway
作者:Xi Huang、Junjie Hu、Mengying Wu、Jiayi Wang、Yanqing Peng、Gonghua Song
DOI:10.1039/c7gc02863f
日期:——
addition and 1,4-reduction of α,β-unsaturatedcarbonylcompounds. Without any metal-catalyst or base, a series of β-boration products of α,β-unsaturatedcarbonylcompounds was easily obtained in moderate to excellent yields in a mixed solvent of ethanol and water. The presence of a catalytic amount of Cs2CO3 can effectively induce further protodeboronation reaction towards 1,4-reduction products at
已开发出一种新颖,有效的无过渡金属且可控制的硼酸化/原硼酸脱硼策略,用于化学选择性结合物的添加和α,β-不饱和羰基化合物的1,4-还原。在没有任何金属催化剂或碱的情况下,在乙醇和水的混合溶剂中,很容易以中等至极好的收率获得一系列α,β-不饱和羰基化合物的β-硼酸酯产物。催化量的Cs 2 CO 3的存在可以在较高的反应温度下有效地引发进一步的原硼酸脱硼反应,生成1,4-还原产物。因此,通过稍微改变反应条件,可控制地获得α,β-不饱和羰基化合物的硼酸化或还原产物。机理研究表明Cs 2CO 3在激活原去硼化步骤中起关键作用。这种无过渡金属催化剂且产物可控的方法为高化学选择性制备α,β-不饱和羰基化合物的β-硼酸酯产物和1,4-还原产物提供了有用且环保的工具。
sp<sup>2</sup>−sp<sup>3</sup> Hybridized Mixed Diboron: Synthesis, Characterization, and Copper-Catalyzed β-Boration of α,β-Unsaturated Conjugated Compounds
作者:Ming Gao、Steven B. Thorpe、Webster L. Santos
DOI:10.1021/ol901359n
日期:2009.8.6
A novel sp2−sp3 hybridized mixed diboron and its reactivity on the copper-catalyzed β-boration of α,β-unsaturated conjugated compounds to afford the corresponding β-borated compounds is reported. The presence of sp3-hybridized boron provides a mild β-boration condition in the absence of phosphine and base additives. Finally, our investigations demonstrate that the sp2-hybridized boron of the mixed
Copper‐Photocatalyzed Hydroboration of Alkynes and Alkenes
作者:Mingbing Zhong、Yohann Gagné、Taylor O. Hope、Xavier Pannecoucke、Mathieu Frenette、Philippe Jubault、Thomas Poisson
DOI:10.1002/anie.202101874
日期:2021.6.21
photocatalytic hydroboration of alkenes and alkynes is reported. The use of newly-designed copper photocatalysts with B2Pin2 permits the formation a boryl radical, which is used for hydroboration of a large panel of alkenes and alkynes. The hydroborated products were isolated in high yields, with excellent diastereoselectivities and a high functional group tolerance under mild conditions. The hydroboration reactions
报道了烯烃和炔烃的光催化硼氢化反应。使用新设计的铜光催化剂和 B 2 Pin 2可以形成硼基自由基,该自由基可用于大量烯烃和炔烃的硼氢化反应。硼氢化产物以高产率分离,在温和条件下具有优异的非对映选择性和高官能团耐受性。硼氢化反应是在连续流动条件下开发的,以证明其合成效用。研究了反应机理,并提出了原位形成的硼酸盐和处于激发态的铜光催化剂之间的氧化反应,以形成硼基自由基。
Cu–tetracatechol metallopolymer catalyst for three component click reactions and β-borylation of α,β-unsaturated carbonyl compounds
作者:Saurabh Joshi、Yong Jie Yip、Tankut Türel、Sandeep Verma、Suresh Valiyaveettil
DOI:10.1039/d0cc05823h
日期:——
advantages of the polymeric catalyst is of interest to the community. Here, we report a simple one pot synthesis of a tetracatechol based ligand and its coordination polymer with copper ions. The Cu polymer showed electrochemical potential with a band gap of 1.01 eV. The BET surface area of the metallopolymer was 91.19 m2 g−1 with 0.14 cm3 g−1 pore volume. The polymer catalyst was used in a one pot three
苯酚-金属配位聚合物可用于催化,传感和分离科学等领域。另外,将环保条件与聚合催化剂的经济和操作优势相结合是社会感兴趣的。在这里,我们报告了一个简单的一锅合成的四儿茶酚基配体及其与铜离子的配位聚合物。Cu聚合物显示出带隙为1.01eV的电化学势。金属聚合物的BET表面积为91.19m 2 g -1和0.14cm 3 g -1孔体积。将该聚合物催化剂用于一锅三组分点击反应和不饱和羰基化合物的硼化中,即使经过4个重复的催化循环,其最大的水转化率和良好的转换效率也达到99%。该聚合物催化剂具有许多优点,例如高活性,易于处理,可扩展性,可回收性和成本效益。