Mark C. McMills

A carbonyl-ylide approach to the tigliane diterpenes

A simple tricyclic oxo-bridged phorbol analog has been synthesized via a 1,3-dipolar cycloaddition from a rhodium initiated metallocarbenoid ylide.

A METALLOCARBENOID APPROACH TO THE FORMATION OF SPIROCYCLIC AMMONIUM YLIDES LEADING TO THE PREPARATION OF MEDIUM-SIZED AZACANE RINGS

Abstract A novel approach to azacyclooctene and azacyclononene containing substrates has been achieved via the intermediacy of a spirocyclic ammonium ylide derived from the diazodecomposition of a tethered α-diazoester moiety.

Facile generation of aziridines from the reaction of α-diazoamides with tethered oximino-ethers

Abstract In an attempt to prepare azomethine ylide intermediates for cycloaddition reactions with electron deficient olefins, oximino-ethers with tethered α-diazoamide moieties were reacted in the presence of metal catalyst. The reaction resulted in aziridine formation preferentially.

Application of diazodecomposition reactions in tandem with [2,3]-sigmatropic rearrangements to prepare substituted azabicyclic ring systems

Stereospecific [2,3]-Sigmatropic rearrangements occurring via ylides generated from the decomposition of α-diazoamides provided good yields of substituted azabicyclo[3.3.0]octanes. In addition some of the non-rearranged cyclopropanes were formed.

Natural products in parallel synthesis: triazole libraries of nonactic acid.

The synthesis of a library of nonactic acid-derived triazoloamide derivatives and their evaluation as antimicrobial agents is described.

Intramolecular cyclopropanation of 7-diazotethered-1,3,5-cycloheptatriene: Preparation and reactions of tricyclo[5.3.0.02,10]deca-3,5-dien-9-one

Abstract The rhodium(II)-catalyzed diazo decomposition of 7-diazocarbonyltethered-1,3,5-cycloheptatriene 3 generated tricyclic ketoester 4 in 64% yield. Reaction of ketoester 4 with nucleophiles leads to cyclopropane cleavage (Nu = PhSNa) to give 5 or rearrangement (Nu = RNH 2 ) to give 7 or 8 .

Novel Cyclization Reactions for η2-Furan Complexes

Abstract A series of complexes has been prepared of the form [Os(NH3)5(4,5-η2-L)]2+ where L=furan and various 2-alkylated furans. Electrophilic addition to C(3) results in an unstable reaction intermediate, a 4,5-η2-3H-furanium species, that leads to several novel cyclization reactions with tethered nucleophiles to form new heterocycles.

Synthesis of highly functionalized arene systems. Novel selectivities of intra- and intermolecular friedel-crafts reactions

ABSTRACT The intermolecular Friedel–Crafts acylation of electron-rich aromatic rings can be difficult in the presence of easily ionized groups. During these studies directed toward the synthesis of colchicine, it was observed that the stability of the cation is key to controlling alternative competing processes.

Synthesis of a Functionalized Oxabicyclo[2.2.1]-Heptene-Based Chemical Library

The 7-oxabicyclo[2.2.1]heptene ring system is a common structural motif in many pharmacologically interesting molecules. We recognized the potential to employ this highly oxygenated and conformationally-restricted scaffold in diversity-oriented synthesis to generate a library of non-chiral but topologically complex compounds. Herein, we report the synthesis and biological evaluation of two 96-member tricyclic libraries containing the oxabicyclo[2.2.1]heptene framework using acetal formation as the key step.

Stereoselective Synthesis of Sulfonyl-substituted trans -2,3-Dihydrofuran Derivatives via Reaction of Arsonium Ylides with α , β -Unsaturated Ketones

Trans-2,3-dihydrofuran derivatives 3 or 4 substituted with a sulfonyl group were prepared with high chemoselectivity and good yields by [1+4]-addition reaction of α,β-unsaturated ketones 1 with arsonium bromide 2 in CH2Cl2 in the presence of potassium carbonate at room temperature. The structures of the products were characterized by IR, MS, 1H NMR, elemental analysis and single crystal X-ray diffraction analysis. A mechanism for the formation of products was also proposed.