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。
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。
Pentamethylphenyl (Ph*) and Related Derivatives as Useful Acyl Protecting Groups for Organic Synthesis: A Preliminary Study
作者:Timothy J. Donohoe、Choon Boon Cheong、James R. Frost
DOI:10.1055/s-0040-1707289
日期:2020.11
A study of acyl protecting groups derived from the Ph* motif is reported. While initial studies indicated that a variety of functional groups were not compatible with the Br2-mediated cleavage conditions required to release the Ph* group, strategies involving the use of different reagents or a modification of Ph* itself (Ph*OH) were investigated to solve this problem.
Synthesis of Cyclopropanes via Hydrogen-Borrowing Catalysis
作者:Jessica L. Crompton、James R. Frost、Sam M. Rowe、Kirsten E. Christensen、Timothy J. Donohoe
DOI:10.1021/acs.orglett.3c01768
日期:2023.7.21
α-cyclopropanation of ketones using hydrogen borrowing (HB) catalysis is described. The transformation occurs via HB alkylation of a hindered ketone with subsequent intramolecular displacement of a pendant leaving group affording the cyclopropanated product. The leaving group can be installed in either the ketone or alcohol component of the HB system, giving access to α-cyclopropyl ketones via two complementary
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。