An expeditious synthesis of α-aryl- and α-alkynylcyclohexenones is described and illustrated by palladium-catalyzed cross-coupling reaction of cyclic α-iodoenones with potassium aryl-trifluoroborate salts. This procedure offers easy access to α-arylated and alkynylated cyclohexenones functionalized with electrondonor and -acceptor substituents in good yields.
Asymmetric Hydrogenation of Racemic 6-Aryl 1,4-Dioxaspiro[4.5]decan-7-ones to Functionalized Chiral β-Aryl Cyclohexanols via a Dynamic Kinetic Resolution
asymmetric hydrogenation method for the synthesis of functionalized β-aryl cyclohexanols is described. With chiral spiro ruthenium catalyst (Ra,S,S)-5c, a series of racemic α-aryl cyclohexanones bearing a β-monoethylene ketal group were hydrogenated to the corresponding functionalized β-aryl cyclohexanols in high yields with enantioselectivity of up to 99% ee via a dynamic kinetic resolution. This protocol
Sequential Michael Addition/Electrophilic Alkynylation: Synthesis of α-Alkynyl-β-Substituted Ketones and Chromanones
作者:Bruno V. M. Teodoro、Luiz F. Silva
DOI:10.1021/acs.joc.8b02251
日期:2018.11.2
α-alkynyl-β-substituted cyclic ketones and analogue chromanones via one-pot Michael addition/hypervalent iodine-based α-alkynylation. Cu(I)-catalyzed Michael addition using either alkyl-aluminum or Grignard reagents, followed by diastereoselective electrophilic alkynylation of the resulting enolate by 1-ethynyl-1λ3,2-benziodoxol-3(1H)-one (EBX) resulted in the α-alkynyl-β-substituted cyclic ketones or chromanones
Phosphine Catalyzed α-Arylation of Enones and Enals Using Hypervalent Bismuth Reagents: Regiospecific Enolate Arylation via Nucleophilic Catalysis
作者:Phillip K. Koech、Michael J. Krische
DOI:10.1021/ja048987i
日期:2004.5.1
Exposure of enones and enals to 20 mol % tributylphosphine in the presence of triarylbismuth(V) dichlorides results in regiospecific aryl transfer to the alpha-position of the enone or enal pronucleophile. These results represent the first examples of enolate arylation under the conditions of nucleophilic catalysis.
An Alternative Approach to <i>para</i>-C–H Arylation of Phenol: Palladium-Catalyzed Tandem γ-Arylation/Aromatization of 2-Cyclohexen-1-one Derivatives
An efficient approach to prepare para-aryl phenols has been developed by using a Pd-catalyzed tandem gamma-arylation/aromatization of 2-cyclohexen-1-one derivatives with aryl bromides. This approach provides various p-aryl phenols from the phenol surrogates, 2-cyclohexen-1-one derivatives, in a single reaction step on the basis of C-H arylation.