Synthesis of Carbazoles by a Diverted Bischler–Napieralski Cascade Reaction
作者:Matteo Faltracco、Said Ortega-Rosales、Elwin Janssen、Răzvan C. Cioc、Christophe M. L. Vande Velde、Eelco Ruijter
DOI:10.1021/acs.orglett.1c00785
日期:2021.4.16
An unforeseen twist in a seemingly trivial Bischler–Napieralskireaction led to the selective formation of an unexpected carbazole product. The reaction proved to be general, providing access to a range of diversely substituted carbazoles from readily available substrates. Judicious variation of substituents revealed a complex cascade mechanism comprising no less than 10 elementary steps, that could
Enantioselective [3+2] coupling of cyclic enamides with quinonemonoimines was realised using a chiralphosphoricacid as a catalyst. This transformation allowed for the synthesis of highly enantioenriched polycyclic 2,3-dihydrobenzofurans...
Alkene Dioxygenation with Malonoyl Peroxides: Synthesis of γ-Lactones, Isobenzofuranones, and Tetrahydrofurans
作者:Carla Alamillo-Ferrer、Marianna Karabourniotis-Sotti、Alan R. Kennedy、Matthew Campbell、Nicholas C. O. Tomkinson
DOI:10.1021/acs.orglett.6b01253
日期:2016.7.1
homoallylic alcohols or carboxylic acids with malonoyl peroxide 1 provides a stereoselective method for the preparation of tetrahydrofurans, γ-lactones, and isobenzofuranones in 44–82% yield and up to 27:1 trans selectivity. Application of this simple and effective heterocyclization in the synthesis of the antidepressant citalopram is also described.
Caesium fluoride-mediated hydrocarboxylation of alkenes and allenes: scope and mechanistic insights
作者:Ashot Gevorgyan、Marc F. Obst、Yngve Guttormsen、Feliu Maseras、Kathrin H. Hopmann、Annette Bayer
DOI:10.1039/c9sc02467k
日期:——
A caesium fluoride-mediated hydrocarboxylation of olefins is disclosed that does not rely on precious transition metal catalysts and ligands. The reaction occurs at atmospheric pressures of CO2 in the presence of 9-BBN as a stoichiometric reductant. Stilbenes, β-substituted styrenes and allenes could be carboxylated in good yields. The developed methodology can be used for preparation of commercial
Enantioselective Epoxidation of β,γ-Unsaturated Carboxylic Acids by a Cooperative Binuclear Titanium Complex
作者:Takahiro Sawano、Hisashi Yamamoto
DOI:10.1021/acscatal.9b00840
日期:2019.4.5
Enantioselective epoxidation of β,γ-unsaturated carboxylicacids with a cooperative binuclear titanium complex has been developed to provide single diastereomer γ-lactones in high yields and enantioselectivities via intramolecular cyclization. For the success of the reaction, the proper distance between the carboxylicacid and alkene is quite important, offering the regioselective epoxidation of unsaturated