Enantioselective Synthesis of Hydrobenzofuranones Using an Asymmetric Desymmetrizing Intramolecular Stetter Reaction of Cyclohexadienones
作者:Qin Liu、Tomislav Rovis
DOI:10.1021/op600278f
日期:2007.5.1
A series of cyclohexadienones were synthesized by dearomatization of phenols followed by Dess-Martin oxidation. Asymmetric intramolecular Stetter reactions of these substrates provide hydrobenzofuranones in good to excellent yields and excellent stereoselectivities. Up to three stereocenters as well as quaternary stereocenter are formed from polysubstituted substrates. A scale up experiment demonstrates
Visible-Light-Mediated Facile Reductive Aromatization of Quinols
作者:Leifeng Wang、Zhiming Yan
DOI:10.1055/s-0035-1561404
日期:——
range of phenols bearing multiple useful functionalities at their meta positions were prepared from the corresponding quinols under the cooperative effects of visible light irradiation, Ru(bpy)3Cl2 photosensitizer, Hunig’s base, LiBF4, and MeCN solvent. The process involves visible-light-enabled photocatalytic cleavage of C–O bond as the strategic event.
Rh-Catalyzed diastereoselective desymmetrization of enone tethered-cyclohexadienones <i>via</i> tandem arylative cyclization
作者:Sandip B. Jadhav、Satish B. Thopate、Jagadeesh Babu Nanubolu、Rambabu Chegondi
DOI:10.1039/c8ob02284d
日期:——
rhodium-catalyzed arylative cyclization of enone tethered-cyclohexadienones has been developed with high efficiency, thus providing cis-fused bicyclic enones in good yields and with excellent diastereoselectivities. Furthermore, this mild transformation has a broad range of substrate scope and excellent functional group tolerance. In addition, bicyclic products have an enone functionality, which can be
Asymmetric Intramolecular Oxa-Michael Reactions of Cyclohexadienones Catalyzed by a Primary Amine Salt
作者:Wenbin Wu、Xin Li、Huicai Huang、Xiaoqian Yuan、Junzhu Lu、Kailong Zhu、Jinxing Ye
DOI:10.1002/anie.201206977
日期:2013.2.4
Michael brings the rings: An asymmetricintramolecular oxa‐Michael reaction involving iminium activation has been developed. This reaction provides enantioenriched 1,4‐dioxane derivatives with up to 99 % yield and 98 % ee. The method allows for concise and stereoselective access to stereodiverse, complex tetracyclic compounds containing a bicyclo[2.2.2]octan‐2‐one backbone with multiple chiral centers
The cascade difunctionalization of α,β-unsaturated carbonyls by nucleophilic halogenation followed by enolate trapping with other electrophiles is highly challenging in synthetic organic chemistry. Herein, we report a chemo- and diastereoselective cascade annulation of enone-tethered cyclohexadienones by using an unconventional combined Lewisacidcatalyzed halogenation reaction in the presence of