3,3‘-Bis(trisarylsilyl)-Substituted Binaphtholate Rare Earth Metal Catalysts for Asymmetric Hydroamination

General Strategy for the Construction of Enantiopure Pyrrolidine-Based Alkaloids. Total Synthesis of (−)-Monomorine

An enantiopure cis-2,5-disubstituted pyrrolidine building block was prepared from cocaine. The synthetic utility of this compound as a chiral building block was demonstrated by a short and efficient synthesis of the pyrrolidine-based alkaloid (-)-monomorine (six steps, 37% overall yield).

Platinum-catalyzed hydrofunctionalization of unactivated alkenes with carbon, nitrogen and oxygen nucleophiles

The transition metal-catalyzed addition of the X-H bond of a carbon, nitrogen or oxygen nucleophile across the C[double bond]C bond of an unactivated alkene (hydrofunctionalization) represents an attractive, atom-economical approach to the synthesis of carbocyclic and heterocyclic molecules and for the elaboration of ethylene and 1-alkenes. We have developed a family of Pt(II)-catalyzed protocols for the inter- and intramolecular hydrofunctionalization of unactivated alkenes with a range of H-X nucleophiles including beta-diketones, indoles, amines, carboxamides and alcohols. These transformations display good functional group compatibility, low moisture sensitivity, and often good generality.

Room Temperature Hydroamination of N-Alkenyl Ureas Catalyzed by a Gold(I) N-Heterocyclic Carbene Complex

[Structure: see text] Treatment of an N-4-pentenyl or N-5-hexenyl urea with a catalytic 1:1 mixture of a gold(I) N,N-diaryl imidazol-2-ylidine complex and AgOTf at or near room temperature leads to intramolecular exo-hydroamination to form the corresponding nitrogen heterocycle in excellent yield.

Gold(I)-catalyzed intramolecular hydroamination of unactivated alkenes with carboxamides

N-Alkenyl carboxamides undergo gold-catalyzed intramolecular exo-hydroamination to form nitrogen heterocycles in excellent yield.

Zirconium Bis(Amido) Catalysts for Asymmetric Intramolecular Alkene Hydroamination

In situ combination of diphosphinic amides and Zr(NMe(2))(4) results in the formation of chiral zirconium bis(amido) complexes. The complexes are competent catalysts for intramolecular asymmetric alkene hydroamintion, providing piperidines and pyrrolidines in up to 80% ee and high yield. This system utilizes an inexpensive zirconium precatalyst and readily prepared ligands and is the first asymmetric alkene hydroamination catalyst based upon a neutral zirconium bis(amido) complex.

Highly Active Au(I) Catalyst for the Intramolecularexo-Hydrofunctionalization of Allenes with Carbon, Nitrogen, and Oxygen Nucleophiles

Reaction of benzyl (2,2-diphenyl-4,5-hexadienyl)carbamate (4) with a catalytic 1:1 mixture of Au[P(t-Bu)2(o-biphenyl)]Cl (2) and AgOTf (5 mol %) in dioxane at 25 degrees C for 45 min led to isolation of benzyl 4,4-diphenyl-2-vinylpyrrolidine-1-carboxylate (5) in 95% yield. The Au(I)-catalyzed intramolecular hydroamination of N-allenyl carbamates tolerated substitution at the alkyl and allenyl carbon atoms and was effective for the formation of piperidine derivatives. gamma-Hydroxy and delta-hydroxy allenes also underwent Au-catalyzed intramolecular hydroalkoxylation within minutes at room temperature to form the corresponding oxygen heterocycles in good yield with high exo-selectivity. 2-Allenyl indoles underwent Au-catalyzed intramolecular hydroarylation within minutes at room temperature to form 4-vinyl tetrahydrocarbazoles in good yield. Au-catalyzed cyclization of N-allenyl carbamates, allenyl alcohols, and 2-allenyl indoles that possessed an axially chiral allenyl moiety occurred with transfer of chirality from the allenyl moiety to the newly formed stereogenic tetrahedral carbon atom.

Base-catalysed asymmetric hydroamination/cyclisation of aminoalkenes utilising a dimeric chiral diamidobinaphthyl dilithium salt

A dimeric proline derived diamidobinaphthyl dilithium salt represents the first example of a chiral main group metal based catalyst for asymmetric hydroamination/cyclisation reactions of aminoalkenes.

A new homogeneous zinc complex with increased reactivity for the intramolecular hydroamination of alkenes

The new zinc compound N-cyclohexyl-2-(cyclohexylamino)troponiminate zinc methyl, [(Cy)2ATI]ZnMe, was synthesized and showed a superior reactivity in the intramolecular hydroamination reaction of non-activated alkenes compared to previously reported homogeneous zinc complexes.