Lewis base-catalyzed three-component Strecker reaction on water. An efficient manifold for the direct alpha-cyanoamination of ketones and aldehydes.

The first three-component organocatalyzed Strecker reaction operating on water has been developed. The manifold utilizes ketones (aldehydes) as the starting carbonyl component, aniline as the primary amine, acetyl cyanide as the cyanide source and N,N-dimethylcyclohexylamine as the catalyst.

A substrate-based folding process incorporating chemodifferentiating ABB' three-component reactions of terminal alkynoates and 1,2-dicarbonyl compounds: a skeletal-diversity-oriented synthetic manifold.

A novel three-component reaction (3CR)-based folding process that is able to generate complexity and skeletal diversity is described. The process utilizes chemodifferentiating organocatalyzed ABB' 3CRs of a terminal conjugated alkynoate (building block) with alpha-dicarbonyl compounds (diversity-generating blocks) to generate an array of different molecular topologies (gamma-lactones, linear propargylic enol ethers, or 1,3-dioxolane rings). Amides and esters behave as efficient reactivity-encoding elements (sigma) of the attached keto functionality. Three chemical properties govern the chemical outcome of this folding process: acidity, nucleophilicity (of the catalyst), and carbonyl electrophilicity. Overall, this substrate-based folding process generates three different molecular architectures from the same modular functionalities (ketones) and under the same reaction conditions (methyl propiolate and tertiary amine). In addition, and very importantly for combinatorial applications, all of the products share a common reactive functionality that allows them to be collective substrates for a subsequent diversity-generating process.

Chemo-differentiating MCRs based on alpha-ketoesters and terminal alkynoates. A homoaldol-based ABB' system.

A novel ABB' 3 component reaction (3-CR) system based on the organocatalyzed homoaldolic condensation of alpha-ketoesters in the presence of terminal conjugated alkynoates is described.

Antiproliferative activity in HL60 cells by tetrasubstituted pyrroles: a structure-activity relationship study.

A number of tetrasubstituted pyrrole derivatives have been synthesized and evaluated for their in vitro antiproliferative activities using the human promyelocytic leukemia cell line HL60. Tetrasubstituted pyrroles are obtained by irradiation of a silica gel absorbed mixture of a conjugated alkynoate and a primary amine. Active compounds exhibited GI50 values in the range 4-45 microM, and only six products showed TGI values within the evaluation range. A structure-activity relationship is also discussed.

Multicomponent domino processes based on the organocatalytic generation of conjugated acetylides: efficient synthetic manifolds for diversity-oriented molecular construction.

The organocatalytic generation of a strong base by the action of a good nucleophile is the base for the in situ catalytic generation of conjugated acetylides in the presence of aldehydes or activated ketones. The method is affordable in a multicomponent, domino format able to generate a chemically diverse set of multifunctionalized adducts that are very well suited for diversity-oriented molecular construction. The domino process involves a nucleophile as catalyst and a terminal conjugated alkyne (H-C[triple chemical bond]C-Z) and an aldehyde or activated ketone as building blocks. The chemical outcome of this process changes dramatically as a function of the nucleophile (tertiary amine or phosphine), temperature, stoichiometry, and solvent. These multicomponent domino processes achieve molecular construction with good atom economy and, very importantly, with an exquisite chemo-differentiating incorporation of identical starting units into the products (nondegenerated chemical output). These properties convert the H-C[triple chemical bond]C-Z unit into a specific building block for diversity-oriented molecular construction. Applications to the modular and diversity-oriented synthesis of relevant heterocycles are discussed. A protocol involving two coupled domino processes linked in a one-pot manner will be discussed as an efficient synthetic manifold for the modular and diversity-oriented construction of multisubstituted nitrogen-containing heterocycles.

A modular, one-pot, four-component synthesis of polysubstituted 1,3-oxazolidines.

A modular, one-pot, two-step, four-component synthesis of polysubstituted 1,3-oxzolidines is described. The method comprises two linked domino processes: an organocatalyzed domino reaction of alkyl propiolate and an aliphatic aldehydes and a microwave-assisted amine addition cyclization domino process. An alternative modular, one-pot, three-step, four-component synthesis has also been developed by linking the organocatalyzed domino process to a sequential amine addition/Yb(OTf)(3)-catalyzed enamine cyclization reaction.