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An enantioselective Biginelli reaction that proceeds by a dual-activation route has been developed by using a combined catalyst of a readily available trans-4-hydroxyproline-derived secondary amine and a Brønsted acid. Aromatic, heteroaromatic, and fused-ring aldehydes were found to be suitable substrates for this multicomponent reaction. The corresponding(More)
The N,N'-dioxide-Sc(III) complex has been applied in the three-component Kabachnik-Fields reaction of aldehydes, 2-aminophenol, and diphenyl phosphite, giving the corresponding alpha-amino phosphonates in good yields with high enantioselectivities (up to 87% ee). The direct Kabachnik-Fields reaction proceeded with extremely high reactivity under mild(More)
An efficient catalytic asymmetric Friedel-Crafts alkylation of indoles with alkylidene malonates has been developed by using a chiral N,N'-dioxide-Sc(OTf)(3) complex as the catalyst (see scheme). Some optically active intermediates containing the indole skeleton have been synthesized, such as indolepropionic acid, tryptamines, and beta-carbolines. The(More)
The first example of central metal controlled reversal of enantioselectivity in asymmetric Friedel-Crafts alkylation of indoles and beta,gamma-unsaturated alpha-ketoesters has been developed. Using the same chiral starting material derived N,N'-dioxides 1a and 1b as ligands, various indole esters 4 were obtained in good to excellent yields and(More)
Mild mannered! A highly diastereo- and enantioselective Mannich-type reaction of glycine Schiff base 1 has been developed by using the N,N'-dioxide L-Cu(II) complex as a catalyst. Various optically active anti-alpha,beta-diamino acid esters were obtained in good yields with up to 96:4 d.r. and 97% ee. This straightforward method features a low catalyst(More)
The theoretically inspired development of a Rh-catalyzed [3 + 2 + 1] carbocyclization of carbon- and heteroatom-tethered alkenylidenecyclopropanes (ACPs) with CO for the stereoselective construction of cis-fused bicyclohexenones is described. This study demonstrates that the ring opening of alkylidenecyclopropane proceeds through a(More)
The development of the stereoselective rhodium-catalyzed [(3+2)+2] carbocyclization of alkynylidenecyclopropanes (ACPs) with substituted allenes is described. This work demonstrates that activated and unactivated allenes preferentially undergo carbometalation at the distal terminus to generate tri- and tetrasubstituted exocyclic olefins with a neutral(More)
A new kind of complex prepared from scandium(III) triflate and l-proline-derived N,N'-dioxides has been developed to catalyze the enantioselective aza-Diels-Alder reaction between 1,3-butadiene (diene 1) and aldimines 2, affording the corresponding 2,5-disubstituted dihydropyridinones in moderate to high yields (up to 92%) with good enantioselectivities (up(More)