The copper-catalyzed [4 + 2] annulation of α,β-unsaturated ketoximeacetates with 1,3-dicarbonyl compounds for the synthesis of three classes of structurally diverse pyridines has been developed. This method employs 1,3-dicarbonyl compounds as C2 synthons and enables the synthesis of multifunctionalized pyridines with diverse electron-withdrawing groups in moderate to good yields. The mechanistic investigation
Tandem Wittig Reaction–Ring Contraction of Cyclobutanes: A Route to Functionalized Cyclopropanecarbaldehydes
作者:Federico Cuccu、Lorenzo Serusi、Alberto Luridiana、Francesco Secci、Pierluigi Caboni、David J. Aitken、Angelo Frongia
DOI:10.1021/acs.orglett.9b02690
日期:2019.10.4
An original tandem reaction consisting of a Wittig reaction-ring contraction process between α-hydroxycyclobutanone and phosphonium ylides has been developed. Highly functionalized cyclopropanecarbaldehydes are obtained in good to high yield.
Organocatalytic selenosulfonylation of the C–C doublebond of α,β-unsaturatedketones to construct two contiguous stereogenic centers in an aqueous medium was described. A series of α-selenyl and β-sulfonyl ketones with various functional groups were synthesized in good yields and enantioselectivities with saturated NaCl solution as the solvent. In addition, this protocol had been successfully scaled
Nonenzymatic Dynamic Kinetic Resolution of <i>in situ</i>
Generated Hemithioacetals: Access to 1,3-Disubstituted Phthalans
作者:Utpal Nath、Deepan Chowdhury、Subhas Chandra Pan
DOI:10.1002/adsc.201701518
日期:2018.4.17
The first nonenzymatic DKR reaction of hemithioacetals is developed. Hemithioacetals were formed in situ via thioladdition and subsequently underwent an intramolecular oxa‐Michael reaction. The scope of the reaction was quite broad ranging from aliphatic to aromatic substituents and 1,3‐disubstituted‐1,3‐dihyroisobenzofuran products were obtained in good yields with moderate diastereoselectivities
Aerobic Oxidative Dehydrogenation of Ketones to 1,4-Enediones
作者:Bao-Yin Zhao、Xing-Long Zhang、Rui-Li Guo、Meng-Yue Wang、Ya-Ru Gao、Yong-Qiang Wang
DOI:10.1021/acs.orglett.0c04174
日期:2021.2.19
An efficient and unprecedented strategy for the synthesis of 1,4-enediones from saturated ketones has been developed via palladium-catalyzedoxidativedehydrogenation. The protocol employs molecular oxygen as the sole oxidant and represents an atom- and step-economic process. The approach showed broad substrate scope, good functional group tolerance, and complete E-stereoselectivity. The reaction mechanism