Acid-Catalyzed Synthesis of α,β-Disubstituted Conjugated Enones by a Meyer-Schuster-Type Rearrangement in Allenols
作者:Benito Alcaide、Pedro Almendros、Sara Cembellín、Teresa Martínez del Campo
DOI:10.1002/adsc.201400928
日期:2015.3.23
A novel, direct and simple methodology to gain access to α,β‐disubstituted conjugated enones from α‐allenols in a sustainable metal catalysis context, considering the inexpensiveness and environmentally friendliness of iron(III) species and protons, has been developed.
Cross Dehydrogenative Coupling via Base-Promoted Homolytic Aromatic Substitution (BHAS): Synthesis of Fluorenones and Xanthones
作者:Sebastian Wertz、Dirk Leifert、Armido Studer
DOI:10.1021/ol4000857
日期:2013.2.15
Cross dehydrogenative coupling reactions occurring via base-promoted homolytic aromatic substitutions (BHASs) are reported. Fluorenones and xanthones are readily prepared via CDC starting with readily available ortho-formyl biphenyls and ortho-formyl biphenylethers, respectively. The commercially available and cheap tBuOOH is used as an oxidant. Initiation of the radical chain reaction is best achieved
N-Heterocyclic carbene/photo-cocatalyzed oxidative Smiles rearrangement: synthesis of aryl salicylates from <i>O</i>-aryl salicylaldehydes
作者:Zi-Hao Xia、Lei Dai、Zhong-Hua Gao、Song Ye
DOI:10.1039/c9cc09272b
日期:——
The N-heterocyclic carbene/photo-cocatalyzed oxidative Smiles rearrangement of O-aryl salicylaldehydes was developed. Both electron-deficient and electron-rich aryls worked well as migrating groups, giving the corresponding aryl salicylates in good yields. This reaction features formation of two new C-O bonds and one C-O bond cleavage via metal-free oxidation of the Breslow intermediate using oxygen
CBr<sub>4</sub> promoted intramolecular aerobic oxidative dehydrogenative arylation of aldehydes: application in the synthesis of xanthones and fluorenones
作者:Jing Tang、Shijun Zhao、Yuanyuan Wei、Zhengjun Quan、Congde Huo
DOI:10.1039/c7ob00080d
日期:——
promoted intramolecular aerobic oxidative dehydrogenative coupling reaction has been developed to provide a straightforward ring closure protocol for 2-aryloxybenzaldehydes to furnish xanthones. The reaction was performed under metal-, additive- and solvent-free conditions with good tolerance of functional groups. The present method is also applicable to the synthesis of fluorenones by using 2-arylbenzaldehydes