103478-12-2Relevant articles and documents
Rapid and Mild Lactamization Using Highly Electrophilic Triphosgene in a Microflow Reactor
Fuse, Shinichiro,Komuro, Keiji,Otake, Yuma,Masui, Hisashi,Nakamura, Hiroyuki
supporting information, p. 7525 - 7532 (2021/03/17)
Lactams are cyclic amides that are indispensable as drugs and as drug candidates. Conventional lactamization includes acid-mediated and coupling-agent-mediated approaches that suffer from narrow substrate scope, much waste, and/or high cost. Inexpensive, less-wasteful approaches mediated by highly electrophilic reagents are attractive, but there is an imminent risk of side reactions. Herein, a methods using highly electrophilic triphosgene in a microflow reactor that accomplishes rapid (0.5–10 s), mild, inexpensive, and less-wasteful lactamization are described. Methods A and B, which use N-methylmorpholine and N-methylimidazole, respectively, were developed. Various lactams and a cyclic peptide containing acid- and/or heat-labile functional groups were synthesized in good to high yields without the need for tedious purification. Undesired reactions were successfully suppressed, and the risk of handling triphosgene was minimized by the use of microflow technology.
Intramolecular Staudinger ligation: A powerful ring-closure method to form medium-sized lactams
David, Olivier,Meester, Wim J. N.,Bieraeugel, Hans,Schoemaker, Hans E.,Hiemstra, Henk,Van Maarseveen, Jan H.
, p. 4373 - 4375 (2007/10/03)
Efficient access to medium-sized lactams from co-amino acids that are resistant to ring-closure by traditional strategies is enabled by an intramolecular Staudinger ligation approach. An undesired premature Staudinger reaction is avoided by protecting the phosphane-containing auxiliary as a borane complex (see scheme; dabco = 1,4-diazabicyclo[2.2.2]octane).
