Syntheses of carbocyclic aminonucleosides and (-)-epi-4'-carbocyclic puromycin: Application of palladium(0)/indium iodide-allylations and tethered aminohydroxylations.

Carbocyclic aminonucleosides and epi-4'-carbocyclic puromycin were prepared from an acylnitroso-derived hetero Diels-Alder cycloadduct. Pd(0)/InI-mediated allylations of a formyl species were used to install the 4'-hydroxymethyl group. A tethered aminohydroxylation strategy was employed to install the cis-2',3'-aminoalcohol moiety with complete regio- and diastereocontrol.

Palladium(0)/indium iodide-mediated allylations of electrophiles generated from the hydrolysis of Eschenmoser's salt: One-pot preparation of diverse carbocyclic scaffolds.

A formyl equivalent was generated in situ from Eschenmoser's salt in aqueous THF and was reacted with an allylindium species. Acylnitroso-derived hetero-Diels Alder adducts and related allyl acetates were shown to be substrates for Pd(0)/InI-mediated allylations of formaldehyde-related species to provide homoallylic alcohols. Hydroxymethyl groups were installed with regio- and diastereocontrol to provide relevant disubstituted carbocyclic scaffolds. Enantiopure anti-disubstituted cyclopentene products were prepared from a chiral allyl acetate.

Palladium-catalyzed decarboxylative rearrangements of allyl 2,2,2-trifluoroethyl malonates: direct access to homoallylic esters.

Homoallylic esters are obtained in a single transformation from allyl 2,2,2-trifluoroethyl malonates by using a Pd(0) catalyst. Facile decarboxylation of allyl 2,2,2-trifluoroethyl malonates is attributed to a decrease in pK(a) compared to allyl methyl malonates. Subsequent reduction of the homoallylic 2,2,2-trifluoroethyl ester provides a (hydroxyethyl)cyclopentenyl derivative that represents a key intermediate in the synthesis of carbocyclic nucleosides. A select allyl 2,2,2-trifluoroethyl malonate undergoes a decarboxylative Claisen rearrangement to provide a regioisomeric homoallylic ester.

Syntheses of carbocyclic uracil polyoxin C analogs: application of Pd(0)/InI-allylation of 4-acetoxy-2-azetidinone.

Carbocyclic uracil polyoxin C analogs are prepared from an acylnitroso-derived hetero Diels-Alder cycloadduct in fewer than nine steps. Pd(0)/InI-mediated allylation of 4-acetoxy-2-azetidinone is used to install the beta-amino acid side chain at the C-5' position of the carbocycle.

Pd(0)/InI-mediated allylic additions to 4-acetoxy-2-azetidinone: new route to highly functionalized carbocyclic scaffolds.

Acylnitroso-derived hetero-Diels-Alder cycloadducts are susceptible to C-O bond cleavage with Pd(0) and InI to form allylic indium(III) species. The in situ prepared allylindium compounds readily react at room temperature with Eschenmoser's salt. Allylation of 4-acetoxy-2-azetidinone provides derivatized cyclopentenes in high regio- and diastereoselectivity.

Titanocene(III) chloride-mediated reductions of oxazines, hydroxamic acids, and N-hydroxy carbamates.

Titanocene(III) chloride (Cp(2)TiCl), generated in situ, reduces N-O bonds of various substrates in good to excellent yields (72-95%). Reactions may be performed with stoichiometric Cp(2)TiCl or with catalytic Cp(2)TiCl.

1,3-Disubstituted-imidazo[1,5-a]pyrazines as insulin-like growth-factor-I receptor (IGF-IR) inhibitors.

A series of novel 8-amino-1,3-disubstituted-imidazo[1,5-a]pyrazines was designed and synthesized as IGF-IR inhibitors.

3-[6-(2-Dimethylamino-1-imidazol-1-yl-butyl)-naphthalen-2-yloxy]-2,2-dimethyl-propionic acid as a highly potent and selective retinoic acid metabolic blocking agent.

3-[6-(2-Dimethylamino-1-imidazol-1-yl-butyl)-naphthalen-2-yloxy]-2,2-dimethyl-propionic acid and analogs were designed and synthesized as highly potent and selective CYP26 inhibitors, serving as retinoic acid metabolic blocking agents (RAMBAs), with demonstrated in vivo efficacy to increase the half-life of exogenous atRA.

Potent and selective [2-imidazol-1-yl-2-(6-alkoxy-naphthalen-2-yl)-1-methyl-ethyl]-dimethyl-amines as retinoic acid metabolic blocking agents (RAMBAs).

A series of [2-imidazol-1-yl-2-(6-alkoxy-naphthalen-2-yl)-1-methyl-ethyl]-dimethyl-amines were designed and synthesized as CYP26 inhibitors, serving as retinoic acid metabolic blocking agents (RAMBA's).

Regio- and stereospecific syntheses of syn- and anti-1,2-imidazolylpropylamines from the reaction of 1,1'-carbonyldiimidazole with syn- and anti-1,2-amino alcohols.

The regio- and stereospecific conversion of syn- and anti-1,2-amino alcohols to their respective syn- and anti-1,2-imidazolylpropylamines via treatment with 1,1'-carbonyldiimidazole is described. The rationale behind the regio- and stereospecific nature as well as the generality of the reaction is discussed.