@article{8dffbe351d2048ee8ca30e46a14a723e,
title = "Stream-lined synthesis of 3-hydroxy-β-lactams: Norrish-Yang type II photocyclizations of β-ketoformamides",
abstract = "A photochemical approach to 3-phenyl-3-hydroxy-β-lactams (3-HβLs) is reported. Irradiation of aryl-β-ketoformamides with a UV light band centered at 300 nm provides the corresponding 3-aryl-3-HβLs with good conversion. The scope of the photocyclization is explored with an electronically diverse panel of substrates that provides mechanistic insight supporting a Norrish-Yang type II cyclization. A flexible synthetic route to phenyl-β-ketoformamides, followed by photoirradiation, allows for efficient incorporation of the β-lactam pharmacophore into aromatic organic scaffolds. Taken collectively, the improved and optimized synthetic route to provide both β-ketoformamides and 3-HβLs—in combination with the expanded analysis of substrate scope and limitations—reported herein will serve as a necessary reference for the direct, atom-economical, radical-mediated installation of 3-HβL scaffolds en route to the generation of other biologically active small molecules.",
keywords = "3-Hydroxy-β-lactams, Norrish-Yang cyclization, Photocyclization, Radical chemistry, β-Ketoformamide formation, β-Lactam synthesis",
author = "Markley, \{Jana L.\} and Morse, \{Tyler L.\} and Rath, \{Nigam P.\} and Wencewicz, \{Timothy A.\}",
note = "Funding Information: The authors thank Dr. Jeff Kao and Dr. Manmilan Singh (WUSTL, Dept. of Chemistry) for assistance with 2D-NMR experiments and Dr. Brad Evans (Danforth Plant Science Center, St. Louis, MO) for acquisition of high-resolution MS spectra (NSF Grant No. DBI-0922879). The X-ray structure determinations were made possible by NSF Instrument Grant No. CHE-042097 (Dr. Nigam Rath, UMSL). In addition, the authors thank Washington University in St. Louis for their financial support of this work and our program. Funding Information: The authors thank Dr. Jeff Kao and Dr. Manmilan Singh (WUSTL, Dept. of Chemistry) for assistance with 2D-NMR experiments and Dr. Brad Evans (Danforth Plant Science Center, St. Louis, MO) for acquisition of high-resolution MS spectra ( NSF Grant No. DBI-0922879 ). The X-ray structure determinations were made possible by NSF Instrument Grant No. CHE-042097 (Dr. Nigam Rath, UMSL). In addition, the authors thank Washington University in St. Louis for their financial support of this work and our program. Publisher Copyright: {\textcopyright} 2018 Elsevier Ltd",
year = "2018",
month = may,
day = "31",
doi = "10.1016/j.tet.2018.04.040",
language = "English",
volume = "74",
pages = "2743--2753",
journal = "Tetrahedron",
issn = "0040-4020",
number = "22",
}