Transition Metal-Free Synthesis of Halobenzo[<i>b</i>]furans from <i>O</i>-Aryl Carbamates via <i>o</i>-Lithiation Reactions
A straightforward and transition metal-free one-pot protocol to synthesize halobenzo[<i>b</i>]furans has been developed employing simple and easily available starting materials such as <i>O</i>-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involv...
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| Format: | Article |
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MDPI AG
2022-01-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/27/2/525 |
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| author | Claudia Feberero Cintia Virumbrales Carlos Sedano Lorena Renedo Samuel Suárez-Pantiga Roberto Sanz |
| author_facet | Claudia Feberero Cintia Virumbrales Carlos Sedano Lorena Renedo Samuel Suárez-Pantiga Roberto Sanz |
| author_sort | Claudia Feberero |
| collection | DOAJ |
| description | A straightforward and transition metal-free one-pot protocol to synthesize halobenzo[<i>b</i>]furans has been developed employing simple and easily available starting materials such as <i>O</i>-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involved was key to achieving a successful one-pot procedure. Initially, a directed <i>ortho</i>-lithiation process, which uses the carbamate as the directed metalation group, was crucial in providing access to <i>O</i>-2-alkynylaryl <i>N,N</i>-diethyl carbamates by a direct alkynylation of the <i>o</i>-lithiated carbamate, with arylsulfonylalkynes as electrophilic reagents. Cyclization of the generated <i>o</i>-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[<i>b</i>]furans. A wide variety of new halobenzo[<i>b</i>]furans has been synthesized and their utility has been demonstrated by their further transformation. |
| first_indexed | 2024-03-10T00:49:37Z |
| format | Article |
| id | doaj.art-10300b781b234bdf8d806e1be3b2f803 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T00:49:37Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-10300b781b234bdf8d806e1be3b2f8032023-11-23T14:53:16ZengMDPI AGMolecules1420-30492022-01-0127252510.3390/molecules27020525Transition Metal-Free Synthesis of Halobenzo[<i>b</i>]furans from <i>O</i>-Aryl Carbamates via <i>o</i>-Lithiation ReactionsClaudia Feberero0Cintia Virumbrales1Carlos Sedano2Lorena Renedo3Samuel Suárez-Pantiga4Roberto Sanz5Área de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, SpainÁrea de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, SpainÁrea de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, SpainÁrea de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, SpainÁrea de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, SpainÁrea de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, SpainA straightforward and transition metal-free one-pot protocol to synthesize halobenzo[<i>b</i>]furans has been developed employing simple and easily available starting materials such as <i>O</i>-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involved was key to achieving a successful one-pot procedure. Initially, a directed <i>ortho</i>-lithiation process, which uses the carbamate as the directed metalation group, was crucial in providing access to <i>O</i>-2-alkynylaryl <i>N,N</i>-diethyl carbamates by a direct alkynylation of the <i>o</i>-lithiated carbamate, with arylsulfonylalkynes as electrophilic reagents. Cyclization of the generated <i>o</i>-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[<i>b</i>]furans. A wide variety of new halobenzo[<i>b</i>]furans has been synthesized and their utility has been demonstrated by their further transformation.https://www.mdpi.com/1420-3049/27/2/525<i>o</i>-lithiationcarbamatesalkynylationbenzo[<i>b</i>]furanscyclization |
| spellingShingle | Claudia Feberero Cintia Virumbrales Carlos Sedano Lorena Renedo Samuel Suárez-Pantiga Roberto Sanz Transition Metal-Free Synthesis of Halobenzo[<i>b</i>]furans from <i>O</i>-Aryl Carbamates via <i>o</i>-Lithiation Reactions Molecules <i>o</i>-lithiation carbamates alkynylation benzo[<i>b</i>]furans cyclization |
| title | Transition Metal-Free Synthesis of Halobenzo[<i>b</i>]furans from <i>O</i>-Aryl Carbamates via <i>o</i>-Lithiation Reactions |
| title_full | Transition Metal-Free Synthesis of Halobenzo[<i>b</i>]furans from <i>O</i>-Aryl Carbamates via <i>o</i>-Lithiation Reactions |
| title_fullStr | Transition Metal-Free Synthesis of Halobenzo[<i>b</i>]furans from <i>O</i>-Aryl Carbamates via <i>o</i>-Lithiation Reactions |
| title_full_unstemmed | Transition Metal-Free Synthesis of Halobenzo[<i>b</i>]furans from <i>O</i>-Aryl Carbamates via <i>o</i>-Lithiation Reactions |
| title_short | Transition Metal-Free Synthesis of Halobenzo[<i>b</i>]furans from <i>O</i>-Aryl Carbamates via <i>o</i>-Lithiation Reactions |
| title_sort | transition metal free synthesis of halobenzo i b i furans from i o i aryl carbamates via i o i lithiation reactions |
| topic | <i>o</i>-lithiation carbamates alkynylation benzo[<i>b</i>]furans cyclization |
| url | https://www.mdpi.com/1420-3049/27/2/525 |
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