Borane-Catalyzed, Chemoselective Reduction and Hydrofunctionalization of Enones Enabled by B–O Transborylation
作者:Kieran Nicholson、Thomas Langer、Stephen P. Thomas
DOI:10.1021/acs.orglett.1c00446
日期:2021.4.2
The use of stoichiometric organoborane reductants in organic synthesis is well established. Here these reagents have been rendered catalytic through an isodesmic B–O/B–H transborylation applied in the borane-catalyzed, chemoselectivealkenereduction and formal hydrofunctionalization of enones. The reaction was found to proceed by a 1,4-hydroboration of the enone and B–O/B–H transborylation with HBpin
A Convergent Construction of Quaternary Centres and Polycyclic Structures
作者:Samir Z. Zard、Grégori Binot、Béatrice Quiclet-Sire、Twana Saleh
DOI:10.1055/s-2003-37110
日期:——
Various xanthates, made by conjugate addition of xanthic acid to electrophilic olefins, add in a inter- or intra-molecular fashion to olefins allowing a direct introduction of a quaternary centres and the construction of polycyclic structures.
A transitionmetal-free domino process has been developed, for the first time, to synthesize (E)-stilbenes, biaryl methanes and biaryl ethers from substituted α,β-unsaturated ketones, benzyl acetones and phenacyl ethers, respectively, in moderate to good yields at roomtemperature using diethyl aluminium chloride (Et2AlCl) as a Lewis acid.
Photocatalytic Stoichiometric Oxidant-Free Synthesis of Linear Unsaturated Ketones from 1,2-Disubstituted Cyclopropanols
作者:Alaksiej L. Hurski、Marharyta V. Laktsevich-Iskryk、Anastasiya V. Krech、Vladimir N. Zhabinskii、Vladimir A. Khripach
DOI:10.1055/s-0040-1706088
日期:2021.3
A one-step catalytic oxidant-free synthesis of unsaturated ketones from 1,2-disubstituted cyclopropanols is reported. Previously for this transformation, only two- and three-step protocols have been developed. The reaction proceeds under irradiation with visible light in the presence of catalytic amounts of both an acridinium photocatalyst and a cobaloxime complex. 2-Aryl-substituted cyclopropanols