https://hdl.handle.net/10259/3594 2026-05-14T11:58:22Z https://hdl.handle.net/10259/11626 Mo‐Catalyzed Synthesis of N‐Polyheterocycles From Functionalized Nitroarenes and Aldehydes Martínez González, Raúl; Rubio Presa, Rubén; Pedrosa Sáez, María de los Remedios; Suárez Pantiga, Samuel; Sanz Díez, Roberto The direct preparation of nitrogen-containing polyaromatic heterocycles in a single operational step from readily availablenitroarenes represents an attractive and sustainable alternative to traditional multistep approaches. In this context, this workdescribes an efficient and versatile methodology for the synthesis of fused N-polyheterocyclic scaffolds from functionalizednitroarenes and aldehydes catalyzed by dioxomolybdenum(VI) complexes and employing pinacol as a readily available andenvironmentally benign reductant. The protocol integrates nitro reduction, imine formation, and intramolecular cyclization ina single operational sequence. Careful fine-tuning of the reaction conditions proved crucial to minimizing competing pathways.This molybdenum-catalyzed strategy exhibits broad substrate scope, accommodating aromatic, aliphatic, and α,β-unsaturatedaldehydes, and enabling access to a variety of pharmaceutically relevant frameworks, such as pyrrolo[1,2-a]quinoxalines,indoloquinoxalines, γ-carbolines, imidazoquinolines, and phenanthridines. 2026-05-01T00:00:00Z https://hdl.handle.net/10259/10507 Transition Metal-Free Synthesis of Halobenzo[b]furans from O-Aryl Carbamates via o-Lithiation Reactions Feberero García, Claudia; Virumbrales Ortiz, Cintia; Sedano Labrador, Carlos; Renedo Peña, Lorena; Suárez Pantiga, Samuel; Sanz Díez, Roberto A straightforward and transition metal-free one-pot protocol to synthesize halobenzo[b]furans has been developed employing simple and easily available starting materials such as O-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involved was key to achieving a successful one-pot procedure. Initially, a directed ortho-lithiation process, which uses the carbamate as the directed metalation group, was crucial in providing access to O-2-alkynylaryl N,N-diethyl carbamates by a direct alkynylation of the o-lithiated carbamate, with arylsulfonylalkynes as electrophilic reagents. Cyclization of the generated o-alkynylaryl carbamates was successfully accomplished through a strategy involving in situ carbamate alkaline hydrolysis under conventional heating or microwave irradiation, coupled with a subsequent heterocyclization step delivering the desired benzo[b]furans. A wide variety of new halobenzo[b]furans has been synthesized and their utility has been demonstrated by their further transformation. 2022-01-01T00:00:00Z https://hdl.handle.net/10259/10506 γ‐Terpinene: Biorenewable Reductant for the Molybdenum‐Catalyzed Reduction of Sulfoxides, N‐Oxides and Nitroarenes Hernández Ruiz, Raquel; Solas Luera, Marta; Suárez Pantiga, Samuel; Pedrosa Sáez, María de los Remedios; Sanz Díez, Roberto A molybdenum-catalyzed deoxygenation of sulfoxides, pyridine and quinoline N-oxides, N-hydroxybenzotriazoles, as well as the reduction of nitroarenes to anilines, has been developed using monocyclic terpenes such as γ-terpinene as an environmentally benign hydrogen surrogate. The only byproducts generated are water and p-cymene, under neat reaction conditions in which the terpene acts as both solvent and reducing agent. These features make this approach a highly attractive and sustainable alternative for the reduction of S-O and N-O containing compounds. Additionally, the reaction exhibited excellent chemoselectivity, tolerating a wide variety of functional groups. 2025-05-01T00:00:00Z https://hdl.handle.net/10259/10505 Molybdenum‐Catalyzed Direct Synthesis of Pyrroles from Nitroarenes with Glycols as Reductants Gómez Gil, Sara; Suárez Pantiga, Samuel; Pedrosa Sáez, María de los Remedios; Sanz Díez, Roberto A molybdenum-catalyzed synthesis of N-(hetero)aryl pyrroles directly from inexpensive and commonly available (hetero)nitroarenes via reduction with pinacol and annulation with 1,4-dicarbonyls or cyclobutane-1,2-diols has been described. The process does not require an inert atmosphere and tolerates the presence of air and water. This non-noble catalytic system shows high chemoselectivity, allowing a diverse range of potentially reducible functional groups such as alkynes, alkenes, halogens, cyano, and carbonyls. Moreover, this strategy enables the reuse of a waste byproduct as reactant, facilitating the formation of challenging 1,4-dicarbonyls from accessible cyclobutane-1,2-diols used as reducing agents. 2024-10-01T00:00:00Z