Hydrogen borrowing catalysis using 1° and 2° alcohols: Investigation and scope leading to α and β branched products
作者:James R. Frost、Choon Boon Cheong、Wasim M. Akhtar、Dimitri F.J. Caputo、Kirsten E. Christensen、Neil G. Stevenson、Timothy J. Donohoe
DOI:10.1016/j.tet.2021.132051
日期:2021.4
variety of ketonesusing 1° or 2° alcohols under hydrogen borrowing catalysis is described. Initial research focused on the α-alkylation of cyclopropyl ketones with higher 1° alcohols (i.e. larger than MeOH), leading to the formation of α-branchedproducts. Our search for additional substrates with which to explore this chemistry led us to discover that di-ortho-substituted aryl ketones were also privileged
描述了在氢借位催化下使用1°或2°醇对各种酮进行的烷基化。最初的研究集中在环丙酮与更高的1°醇(即大于MeOH)的α-烷基化反应上,导致形成α-支化产物。我们通过寻找其他底物来探索这种化学反应,使我们发现,二邻位取代的芳基酮也是特有的支架,其中Ph ∗(C 6 Me 5)酮是最佳选择。进一步的研究表明,该基序对于与2°醇形成β支链产物的烷基化至关重要,这也为研究非对映选择性和分子内氢借入过程提供了机会。
Strategic Application and Transformation of <i>ortho</i>-Disubstituted Phenyl and Cyclopropyl Ketones To Expand the Scope of Hydrogen Borrowing Catalysis
作者:James R. Frost、Choon Boon Cheong、Wasim M. Akhtar、Dimitri F. J. Caputo、Neil G. Stevenson、Timothy J. Donohoe
DOI:10.1021/jacs.5b11196
日期:2015.12.23
The application of an iridium-catalyzed hydrogen borrowing process to enable the formation of α-branched ketones with higher alcohols is described. In order to facilitate this reaction, ortho-disubstituted phenyl and cyclopropylketones were recognized as crucial structural motifs for C-C bond formation. Having optimized the key catalysis step, the ortho-disubstituted phenyl products could be further
描述了铱催化的借氢过程在能够与高级醇形成 α-支化酮中的应用。为了促进该反应,邻位双取代的苯基和环丙基酮被认为是 CC 键形成的关键结构基序。在优化了关键催化步骤后,邻位二取代苯基产物可以通过反弗里德尔-克来福特酰化反应进一步操作,以产生合成有用的羧酸衍生物。相比之下,环丙基酮与几种亲核试剂进行同共轭加成,以提供进一步功能化的支化酮产物。
Michiels, Chemisches Zentralblatt, 1912, vol. 83, # I, p. 1105
作者:Michiels
DOI:——
日期:——
A highly diastereoselective synthesis of (E)-B-2-(1-cyclopropyl-1-alkenyl)-1,3,2-dioxaborinanes. Isolation and oxidation to alkyl cyclopropyl ketones
作者:Narayan G. Bhat、Laura Garcia、Victoriano Tamez
DOI:10.1016/s0040-4039(03)01841-0
日期:2003.9
A convenient, novel synthesis of alkyl cyclopropylketones based on Z-1-bromo-1-alkenylboronate esters is developed. α-Bromo-(Z)-1-alkenylboronate esters readily available from literature procedures smoothly undergo a reaction with cyclopropylmagnesium bromide in tetrahydrofuran to provide the corresponding ‘ate’ complexes. These ‘ate’ complexes undergo intramolecular nucleophilic substitution reactions