A highly efficient asymmetric ring-opening reaction of cyclopropyl ketones with a broad range of thiols, alcohols and carboxylic acids has been first realized by using a chiral N,N'-dioxide-scandium(III) complex as catalyst. The corresponding sulfides, ethers, and esters were obtained in up to 99% yield and 95% ee. This is also the first example of one catalytic system working for the ring-opening reaction of donor-acceptor cyclopropanes with three different nucleophiles, let alone in an asymmetric version.

A highly efficient asymmetric ring-opening/cyclization/retro-Mannich reaction of cyclopropyl ketones with aryl 1,2-diamines has been realized using a chiral N,N'-dioxide/Sc(III) catalyst. Benzimidazoles containing chiral side chains were generated under mild reaction conditions in excellent outcomes (up to 99 % yield and 97 % ee). This method also provides efficient access to chiral benzimidazole-substituted amide and cycloheptene derivatives.

No abstract

A chiral N,N′-dioxide/Tb(OTf)3 complex catalyzed diastereo- and enantioselective [4+3] cycloaddition of ortho-quinone methides with oxiranes has been described in this study.

Highly enantioselective C2 alkylation and inverse-electron-demand [3 + 2]-cycloaddition of 3-methylindoles with 2,2′-diester aziridine were accomplished. The chemodivergent synthesis provided an access to two kinds of chiral indole derivatives in good yields and stereoselectivities in the presence of the chiral N,N′-dioxide/Tm­(OTf)3 or N,N′-dioxide/Ho­(OTf)3 complexes. An eight-coordinated mode of N,N′-dioxide/Tm­(OTf)3 complex was confirmed by X-ray crystal diffraction to interpret the roles of additives H2O and 1,4-dioxane. In addition, the control experiments indicated that the substituent of the indole nitrogen atom determined the conversion patterns in the divergent reactions.

An efficient asymmetric ring-opening reaction of cyclopropyl ketones with 2-naphthols has been realized using a chiral N,N′-dioxide–ScIII complex catalyst. A variety of chiral β-naphthol derivatives were obtained in excellent outcomes (up to 99% yield, 97% ee).

Utilizing the C4 reactive site of cyclopropyl ketones and a chiral N,N′-dioxide-scandium(III) complex as catalyst, a concise ring-opening/cyclization/thio-Michael cascade method was developed for the synthesis of chiral benzothiazole derivatives from...

Ahighly efficient asymmetric ring-opening reaction of cyclopropyl ketones with ab road range of thiols,a lcohols and carboxylica cids has been first realized by using ac hiral N,N'-dioxide-scandium(III) complex as catalyst. The corresponding sulfides,e thers,a nd esters were obtained in up to 99 %y ield and 95 %e e. This is also the first example of one catalytic system working for the ring-opening reaction of donor-acceptor cyclopropanes with three different nucleophiles,l et alone in an asymmetric version.Cyclopropanes have proven to be powerful synthetic building blocks.[1] In particular, the ring-opening reactions of donor-acceptor (D-A) cyclopropanes [2][3][4][5][6][7] provide access to am yriad of functionalized carbon skeletons and have attracted extensive attention. Ring-opening reactions initiated by sulfur-and oxygen-containing nucleophiles have been found to be avery useful transformation in the synthesis of gthio and g-oxy functionalized carbonyls. [8,9] Fore xample,t he (S)-proline and Ca(acac) 2 -catalyzed racemic reaction with thiol nucleophiles were reported by Wang [7k] and Nolin,