First anti‐Selective Direct Michael Addition of α‐Alkoxy Ketones to Enones by Cooperative Catalysis of Samarium(III) Trifluoromethanesulfonate and Tributyltin Methoxide

Abstract

A new highly anti‐diastereoselective Michael addition of α‐alkoxy ketones to α,β‐unsaturated ketones was achieved. This method features a dual‐catalyst protocol that combines samarium(III) trifluoromethanesulfonate and Bu3SnOMe. The combination of these two catalysts effectively allowed the generation of enolate species from α‐alkoxy ketones and produced Michael adducts in high yields with high anti diastereoselectivity. A variety of enones and α‐alkoxy ketones were applied to this system to give the anti products. One‐pot domino Michael/aldol reactions effectively afforded cyclic enones with a defined configuration.

Electrochemical Radical Reactions of Enol Acetates and Free Alcohols Directly Access to α-Alkoxylated Carbonyl Compounds

“…. 35 White solid (26 mg; 65% yield) was obtained by the purification with flash column chromatography on silica gel (EtOAc/petroleum ether = 1:10), mp 66−67 °C; 2-Methoxy-2,3-dihydro-1H-inden-1-one (3m). 13 Yellow oil (28 mg; 86% yield) was obtained by the purification with flash column chromatography on silica gel (EtOAc/petroleum ether = 1:10); 1 2-Methoxy-3,4-dihydronaphthalen-1(2H)-one (3n).…”

Samarium(III) Triflate in Organic Synthesis: a Mild and Efficient Catalyst

“…[49,50] ). [51] This methodology was useful to several types of enones to furnish 1,5-dicarbonyl compounds 22 in high yields with high anti diastereoselectivity. Besides, a variety of cyclic enones were synthesized through the direct Michael addition/intramolecular aldol condensation sequence successfully.…”

“…accomplished the first anti ‐diastereoselective Michael addition of α‐alkoxy ketones 19 to enones 20 in the presence of the Sm(OTf) 3 /Bu 3 SnOCH 3 cooperative catalysis to afford Michael adduct 22 through the formation of the chelate intermediate 21 in 2017 (Scheme 10). [51] This methodology was useful to several types of enones to furnish 1,5‐dicarbonyl compounds 22 in high yields with high anti diastereoselectivity. Besides, a variety of cyclic enones were synthesized through the direct Michael addition/intramolecular aldol condensation sequence successfully.…”