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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Synthesis of β-Quaternary Lactams Using Photoenzymatic Catalysis
Joshua R Turek-Herman1, Mike Rosenberger1, Todd K Hyster1
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.
Abstract:
Quaternary carbons are useful motifs in chemical synthesis but can be challenging to prepare using many chemical methods. Here, we report a stereoselective synthesis of β-quaternary lactams using flavin-dependent 'ene'-reductases via a 5-exo-trig radical cyclization. The products are formed in moderate to good levels of enantioselectivity using an 'ene'-reductase variant from Zymomonas mobilis. This method highlights the opportunity for biocatalysis to form quaternary centers using non-natural reactions.
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