Relay Catalysis To Synthesize β-Substituted Enones: Organocatalytic Substitution of Vinylogous Esters and Amides with Organoboronates
作者:Sasha Sundstrom、Thien S. Nguyen、Jeremy A. May
DOI:10.1021/acs.orglett.9b04584
日期:2020.2.21
Organocatalysis was shown to facilitate conjugate additions to vinylogousesters and amides for the first time. Subsequent elimination of a β-alcohol or amine provided π-conjugated β-substituted enones. Remarkably, nucleophile addition to the electron-rich vinylogous substrates is more rapid than classical enones, forming monosubstituted products. A doubly organocatalytic (organic diol and methyl aniline)
Electro‐Olefination—A Catalyst Free Stereoconvergent Strategy for the Functionalization of Alkenes
作者:Andreas N. Baumann、Arif Music、Jonas Dechent、Nicolas Müller、Thomas C. Jagau、Dorian Didier
DOI:10.1002/chem.202001394
日期:2020.7.8
Conventional methods carrying out C(sp2)−C(sp2) bondformations are typically mediated by transition‐metal‐based catalysts. Herein, we conceptualize a complementary avenue to access such bonds by exploiting the potential of electrochemistry in combination with organoboron chemistry. We demonstrate a transition metal catalyst‐free electrocoupling between (hetero)aryls and alkenes through readily available
Brønsted Acid Catalyzed Homoconjugate Addition of Organotrifluoroborates to Arylated Cyclopropyl Ketones
作者:Truong N. Nguyen、Thien S. Nguyen、Jeremy A. May
DOI:10.1021/acs.orglett.6b01795
日期:2016.8.5
A novel and practical homoconjugate addition of alkenyl, alkynyl, heteroaryl, and aryl trifluoroborates to arylated cyclopropylketones to synthesize γ,γ-disubstituted ketones is reported. A preliminary mechanistic proposal involving ketone protonation, an intermediary carbocation, and intermolecular nucleophile addition has been made based on control studies.
Organocatalytic Vinyl and Friedel−Crafts Alkylations with Trifluoroborate Salts
作者:Sandra Lee、David W. C. MacMillan
DOI:10.1021/ja0767480
日期:2007.12.1
pathway. Boronic acids can also be employed as viable π-nucleophiles for these asymmetric conjugate additions provided that in situ activation to the corresponding boronate species is accomplished. While BF3K salts are routinely employed in transition metal catalysis, to our knowledge, this is the first use of this activation group for organic catalysis or Friedel−Crafts alkylations.
Photocatalyzed Transition‐Metal‐Free Oxidative Cross‐Coupling Reactions of Tetraorganoborates**
作者:Arif Music、Andreas N. Baumann、Florian Boser、Nicolas Müller、Florian Matz、Thomas C. Jagau、Dorian Didier
DOI:10.1002/chem.202005282
日期:2021.3
salts undergo selective coupling reactions under blue light irradiation in the presence of catalytic amounts of transition‐metal‐free acridinium photocatalysts to furnish unsymmetrical biaryls, heterobiaryls and arylated olefins. This represents an interesting conceptual approach to forge C−C bonds between aryl, heteroaryl and alkenyl groups under smooth photochemical conditions. Computational studies