Efficient synthesis of alkylboronic esters <i>via</i> magnetically recoverable copper nanoparticle-catalyzed borylation of alkyl chlorides and bromides
作者:Mahadev L. Shegavi、Abhishek Agarwal、Shubhankar Kumar Bose
DOI:10.1039/d0gc00677g
日期:——
report a magnetically separable Cu nanocatalyst (Fe-DOPA-Cu) for the borylation of alkyl halides with alkoxy diboron reagents, providing alkylboronic esters in high yields, with broad functional group tolerance under mild reaction conditions. The procedure is also applicable to the borylation of benzyl chlorides and bromides. Radical clock experiments support a radical-mediated process. Easy recycling of
Cu‐Catalyzed Hydroxymethylation of Unactivated Alkyl Iodides with CO To Provide One‐Carbon‐Extended Alcohols
作者:Siling Zhao、Neal P. Mankad
DOI:10.1002/anie.201801814
日期:2018.5.14
We have developed a reductive carbonylation method by which unactivated alkyliodides can be hydroxymethylated to provide one‐carbon‐extended alcohol products under Cu‐catalyzed conditions. The method is tolerant of alkyl β‐hydrogen atoms, is robust towards a wide variety of functional groups, and was applied to primary, secondary, and tertiary alkyliodide substrates. Mechanistic experiments indicate
NiH-Catalyzed Reductive Relay Hydroalkylation: A Strategy for the Remote C(sp<sup>3</sup>
)−H Alkylation of Alkenes
作者:Fang Zhou、Jin Zhu、Yao Zhang、Shaolin Zhu
DOI:10.1002/anie.201712731
日期:2018.4.3
The terminal‐selective, remoteC(sp3)−H alkylation of alkenes was achieved by a relay process combining NiH‐catalyzed hydrometalation, chain walking, and alkylation. This method enables the construction of unfunctionalized C(sp3)−C(sp3) bonds under mild conditions from two simple feedstock chemicals, namely olefins and alkyl halides. The practical value of this transformation is further demonstrated
Silver(I)-mediated oxidation/cyclization of acrylamides with alkyl trifluoroborates
作者:Siyi Ding、Huaping Ren、Min Zhu、Qiang Ma、Zongcheng Miao、Pengfei Li
DOI:10.1080/00397911.2020.1846057
日期:2021.2.16
A mild silver-mediated oxidative cyclization of acrylamides has been developed by using alkyltrifluoroborates as radical precursors. It proceeds through a tandem radical addition/cyclization proce...
Vinyl Azides as Radical Acceptors in the Vitamin B<sub>12</sub>-Catalyzed Synthesis of Unsymmetrical Ketones
作者:Krzysztof R. Dworakowski、Sabina Pisarek、Sidra Hassan、Dorota Gryko
DOI:10.1021/acs.orglett.1c03321
日期:2021.12.3
Vinyl azides are very reactive species and as such are useful building blocks, in particular, in the synthesis of N-heterocycles. They can also serve as precursors of ketones. These form in reactions of vinyl azides with nucleophiles or radicals. We have found, however, that under light irradiation vitamin B12 catalyzes the reaction of vinyl azides with electrophiles to afford unsymmetrical carbonyl
乙烯基叠氮化物是非常活泼的物质,因此是有用的结构单元,特别是在N-杂环的合成中。它们还可以作为酮的前体。这些是在乙烯基叠氮化物与亲核试剂或自由基的反应中形成的。然而,我们发现,在光照射下,维生素 B 12催化乙烯基叠氮化物与亲电子试剂的反应,以良好的产率提供不对称羰基化合物。机理研究表明烷基自由基是这种转变的关键中间体。