Air-tolerant photoredox catalysis in the synthesis of γ- and δ-lactams from N-alkenyl trichloro- and dichloroacetamides
Gisela Trenchs, Faïza Diaba University of Barcelona, Spain
During the last decade new synthetic approaches to lactams from N -alkenyl trichloroacetamides using radical chemistry were developed.1 The reactions were carried out under reductive conditions (TBTH or TTMSS and AIBN)2 or Atom transfer radical cyclizations in the presence of copper or ruthenium catalysts.3 As part of our ongoing interest in finding new sustainable and green processes to access the above mentioned heterocycles, herein we report the first blue light-mediated synthesis of γ- and δ-lactams from trichoroacetamides in the presence of fac -Ir(ppy) 3 . Unlike previous photoredox works in this field, this procedure is achieved under an air atmosphere with non-anhydrous solvents and even in water. Moreover, besides confirming the radical mechanism of the photoredox reaction, we have demonstrated that the solvent can be the hydrogen donor in the radical process which opens new insights into these radical transformations and the reaction mechanisms involved.4
References 1. Coussanes, G.; Vila, X.; Diaba, F.; Bonjoch, J. Synthesis 2017 , 49, 1481. 2. Jansana, S.; Diaba,F.; Bonjoch, J. Org. Lett . 2019 , 21, 5757. 3. Diaba, F.; Martínez-Laporta, A.; Bonjoch, J. J. Org. Chem . 2014 , 79, 9365. 4. Trenchs, G.; Diaba, F. Org. Biomol. Chem. 2022 , 20, 3118.
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© The Author(s), 2022
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