Practical metal-free synthesis of chalcone derivatives via a tandem cross-dehydrogenative-coupling/elimination reaction
作者:Yu Wei、Jinghua Tang、Xuefeng Cong、Xiaoming Zeng
DOI:10.1039/c3gc41403e
日期:——
Metal-free synthesis of chalcone derivatives through a tandem cross-dehydrogenative-coupling/eliminationreaction is described. A simple and inexpensive ammonium persulfate salt enables the reaction between ketones and benzylamines to proceed with high stereoselectivity and good functional group compatibility.
Cross-coupling of alcohols to value-added products by using sustainable catalytic reactions has gained attention in recent years. Isomerization of secondary allylic alcohol to the corresponding enolizable ketone is an atom economical and known transformation. Herein, a selective cross-coupling of secondary allylic alcohol and primary alcohol is reported to afford the corresponding α-alkenyl or alkylation
Alkynes react with organoborons under a CO atmosphere in the presence of a rhodium(I) catalyst to afford mainly 5-aryl-2(5H)-furanones, α,β-unsaturated ketones, and indanones. The product selectivity can be tuned by modifying the reaction conditions.
The rhodium(I)-catalyzed reaction of alkynes with arylboronic acids in the presence of formaldehyde resulted in a carbon monoxide gas-free carbonylative arylation to yield α,β-enones. The simultaneous loading of phosphine-ligated and phosphine-free rhodium(I) complexes is required for efficient catalysis, which catalyze the abstraction of a carbonyl moiety from formaldehyde (decarbonylation) and its
β-Phenyl Quenching of Triplet Excited Ketones: How Critical Is the Geometry for Deactivation?
作者:Subhas Samanta、Brijesh Kumar Mishra、Tamara C. S. Pace、Narayanasami Sathyamurthy、Cornelia Bohne、Jarugu Narasimha Moorthy
DOI:10.1021/jo060200e
日期:2006.6.1
The phenomenon of β-phenyl quenching has been examined by laser-flash photolysis in a series of α- and/or β-substituted ketones 4−8 with similar excited-state characteristics. It is found that α-substitution markedly increases the triplet lifetimes in contrast to β-substitution. The force field calculations for the various staggered conformers of ketones 4−6 and 8-syn show that the lowest-energy conformation