A novel one-pot sequential transformation via decarboxylative Mannich reaction (DMR) and oxidative C-H amination of cyclic imines with β-ketoacids is described. This methodology has been utilized to provide access to fused aziridines with excellent diastereoselectivity. Several examples of catalytic enantioselective sequential transformation are presented.

The first example of direct reductive amination (DRA) of ketones with electron-deficient amines (EDA) such as Cbz-, Boc-, EtOCO-, Fmoc-, Bz-, ArSO2-, etc. protected amines have been achieved using catalytic Re2O7/NaPF6. Excellent chemoselectivities as well as diastereoselectivity (for 2-alkyl cyclohexanones) were obtained.

Herein we describe a scalable approach to the decalin moiety of maklamicin. Key to the synthesis is an intramolecular Diels-Alder (IMDA) reaction that proceeds via an endo-axial transition state to generate the desired stereochemistry. We explored the diastereoselectivity of the IMDA reaction as a function of both chiral catalysis and acyclic precursor stereochemistry.

An unusual example of diastereoselectivity has been observed in Cu(κ(3)-P,C,P'-1)X complexes where 1 is an asymmetric tridentate ligand containing a bicyclic NHC framework and X is a halide. When X is Cl(-), the S(Cu) isomer is formed selectively whereas when X = I(-) the R(Cu) diastereomer is preferred.

An enantioselective four-component reaction of a diazoketone, water, an aniline and ethyl glyoxylate in the presence of catalytic Rh2(OAc)4 and a chiral Brønsted acid was developed to efficiently produce β-hydroxy-α-amino acid derivatives in good yields with high diastereoselectivity and enantioselectivity.

A versatile and high-yielding indium trichloride mediated cyclization reaction of silylated homoallylic alcohols, thiols, or amines with aldehydes or epoxides is described as a rapid route to a range of unsaturated heterocycles. The excellent diastereoselectivity observed offers a method of wide scope and generality.

A dianionic Ireland-Claisen rearrangement of chiral, nonracemic α-methyl-β-hydroxy allylic esters has been developed that proceeds with high diastereoselectivity and provides products containing three contiguous stereogenic carbons, including a quaternary center. The potential utility of the rearrangement for complex molecule synthesis is also demonstrated.

An organocatalytic quadruple cascade initiated by a Friedel-Crafts-type reaction is described. The (S)-diphenylprolinol trimethylsilyl ether catalyzed reaction yields highly functionalized cyclohexenecarbaldehydes bearing a 1,1-bis[4-(dialkylamino)phenyl]ethene moiety and three contiguous stereogenic centers. The reaction tolerates various functional groups and all products are obtained with ve...

4-Substituted tryptophan derivatives and the total synthesis of cis-clavicipitic acid were achieved in reactions in which Ir-catalyzed C-H bond activation was a key step. The starting material for these reactions is asparagine, which is a cheap natural amino acid. The reductive amination step from the 4-substituted tryptophan derivative gave cis-clavicipitic acid with perfect diastereoselectivity.

A safe and convenient protocol was developed for in situ generation of various dichlorinating agents (cf. Cl2, NCl3, Et4NCl3, ArICl2) from oxone and chloride. The synthetic utility of this protocol was demonstrated by diastereoselective dichlorination of a series of allylic and homoallylic alcohol derivatives with excellent yields and diastereoselectivity.