Sequential Ytterbium(III) Triflate Catalyzed One‐Pot Three‐Component Thia‐Michael Addition

Abstract

Ay tterbium(III) trifluoromethanesulfonate catalyzed one-pot three-component thia-Michael addition reaction of thiolate salts, organic halides, and a,b-unsaturated compoundsh as been developed for the formationo f carbon-sulfur bonds. In this study,p otassium thioacetate serves as the sulfur source in an ucleophilic substitution reaction, which is followed by aY b(OTf) 3 -catalyzed (OTf = trifluoromethanesulfonate) S-deacetylation and subsequent thia-Michael addition reaction. Three important pharmaceutical derivatives were successfully prepared by using the intramolecular version of this one-pot thia-Michael addition reaction. The advantages of this Yb III -catalyzed process include its operational simplicity,i ts capacity towards the preparation of structurally diverse products in 40-93 %y ield, itsu se of relativelyl ow toxic or nontoxic reagents, and its catalyst loading of only 1-2 mol %.Scheme1.Synthetic methods for thia-Michael addition (EWG = electronwithdrawing group, SDS = sodium dodecyls ulfate, Ts = para-toluenesulfonyl, and PEG = polyethylene glycol).

Cerium(III) triflate–catalyzed cycloaddition reaction in aqueous conditions to substituted naphthotriazolediones

“…[ 9 ] Herein, a proposed reaction mechanism for the synthesis of naphthotriazolediones under catalyst‐assisted conditions is illustrated in Scheme 3. [ 9,19 ] The reaction can be explained as being initiated by the Ce(OTf) 3 ‐catalyzed cycloaddition of 1,4‐naphthoquinone 1 and azides 2 . First, the Ce III catalyst activates the α,β‐unsaturated carbonyl system, and a Michael addition reaction is subsequently performed to generate an intermediate A .…”

“…[9] Herein, a proposed reaction mechanism for the synthesis of naphthotriazolediones under catalyst-assisted conditions is illustrated in Scheme 3. [9,19] The reaction can be explained as being initiated by the Ce(OTf) 3 -catalyzed cycloaddition of 1,4-naphthoquinone 1 and azides 2.…”

“…[ 15a ] In addition, lanthanide triflate–catalyzed reactions have become a versatile tool for synthesis due to the high oxophilicity, high water compatibility, and recyclability of lanthanide triflate. [ 17 ] On the basis of our experiences with lanthanide(III) triflate catalysts used in organic reactions, [ 17f,17g,19 ] we herein report that naphtho[2,3‐ d ][1,2,3]triazole‐4,9‐diones can be efficiently synthesized through the cerium(III) triflate [Ce(OTf) 3 ]–catalyzed cycloaddition of 1,4‐naphthoquinone with azides in aqueous solutions (Scheme 1b).…”

Rh(III)-Catalyzed Dual C–H Functionalization and C–O/C–N Annulations of Monoamide Fumarates

“…Methyl (E)-4-oxo-4-(phenylamino)but-2-enoate (1d). 14 Prepared from the typical procedure (Hex/EtOAc = 2:1) to afford the title compound as a white solid with a 60% yield (4.92 g). Mp.…”