[reaction: see text] The enantioselective copper(II)-catalyzed Friedel-Crafts addition of indoles to N-sulfonyl aldimines was developed using chiral bisoxazoline as ligands, and high enantioselectivities (up to 96% ee) were achieved.
Asymmetric Isothiourea-Catalysed Formal [3+2] Cycloadditions of Ammonium Enolates with Oxaziridines
作者:Siobhan R. Smith、Charlene Fallan、James E. Taylor、Ross McLennan、David S. B. Daniels、Louis C. Morrill、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1002/chem.201501271
日期:2015.7.13
A highly enantioselective Lewis base‐catalysed formal [3+2] cycloaddition of ammonium enolates and oxaziridines to give stereodefined oxazolidin‐4‐ones in high yield is described. Employing an enantioenriched oxaziridine in this process leads to a matched/mis‐matched effect with the isothiourea catalyst and allowed the synthesis of either syn‐ or anti‐stereodefined oxazolidin‐4‐ones in high d.r., yield
Lewis base-catalyzed perfluoroalkylation of carbonyl compounds and aldimines with (perfluoroalkyl)trimethylsilanes (TMSCF3, TMSC2F5, and TMSC3F7) is described. The nitrogen- or oxygen-containing an...
Cycloadditions of <i>N</i>-Sulfonyl Nitrones Generated by Lewis Acid Catalyzed Rearrangement of Oxaziridines
作者:Katherine M. Partridge、Mary E. Anzovino、Tehshik P. Yoon
DOI:10.1021/ja711335d
日期:2008.3.1
We have developed cycloaddition reactions of novel, electron-deficient N-nosyl nitrones that arise from the titanium(IV)-catalyzed rearrangement of the corresponding N-nosyl oxaziridines. A diverse range of styrenes and oxaziridines react smoothly in this transformation, producing structurally varied N-nosyl isoxazolidines in good yields and with excellent diastereoselectivity. Importantly, the nosyl
Chiral Copper Complexes of Phosphino Sulfenyl Ferrocenes as Efficient Catalysts for Enantioselective Formal Aza Diels−Alder Reactions of <i>N</i>-Sulfonyl Imines
作者:Olga García Mancheño、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1021/ja038494y
日期:2004.1.1
catalytic amount of silver perchlorate, copper(I) bromide complexes of planar chiral 1-phosphino-2-sulfenylferrocenes behave as very efficient chiral Lewis acids catalysts in the formal Aza Diels-Alder reaction of N-arylsulfonyl aldimines with electron-rich dienes (Danishefsky's and related dienes). Mixing of equimolar amounts of the readily available enantiopure ferrocenyl P,S-bidentate ligand and CuBr quantitatively