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oai:riubu.ubu.es:10259/105072025-05-29T00:05:20Zcom_10259_3593com_10259_5086com_10259_2604col_10259_3594

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 o-Lithiation Carbamates Alkynylation Benzo[b]furans Cyclization Química Chemistry 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. This research was funded by the Ministerio de Ciencia e Innovación and FEDER (PID2020-115789GB-C21), and Junta de Castilla y León and FEDER (BU049P20). The project leading to these results has also received funding from “la Caixa” Foundation, under Agreement LCF/PR/PR18/51130007 > (CAIXA-UBU001). S.S.-P. and C.V. thank Junta de Castilla y León (Consejería de Educación) and Fondo Social Europeo (ESF+) for postdoctoral contracts. C.S. thanks Ministerio de Educación for a FPU predoctoral contract. 2025-05-28T07:39:34Z 2025-05-28T07:39:34Z 2022-01 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/10259/10507 10.3390/molecules27020525 1420-3049 eng Molecules. 2022, V. 27, n. 2, p. 525-545 https://doi.org/10.3390/molecules27020525 Atribución 4.0 Internacional http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess application/pdf MDPI