01469nas a2200193   4500008004100000022001400041245017400055210006900229260000900298300001400307490000700321520070700328100002101035700002001056700002101076700002501097700002401122856012901146       2021                        eng d  a0022-326300aAnnulation of enals with carbamoylpropiolates via NHC-catalyzed enolate pathway: access to functionalized maleimides/iso-maleimides and synthesis of aspergillus FH-X-2130 aAnnulation of enals with carbamoylpropiolates via NHCcatalyzed e  cJUL   a9466-94770 v863 aHerein we report the N-heterocyclic carbene (NHC)-catalyzed [3 + 2] annulation of alpha,beta-unsaturated aldehydes with carbamoylpropiolates via an unusual enolate pathway leading to the construction of highly functionalized maleimides or isomaleimides. The electronic effect imposed by the alkyl/aryl group present on the amide nitrogen of carbamoylpropiolates plays a crucial role in the selective formation of these important five-membered heterocyclic building blocks. The developed protocol is mild and tolerates a wide range of substituents on both substrates. The application of this protocol in the synthesis of the antibacterial natural product Aspergillus FH-X-213 has also been demonstrated.1 aViveki, Amol, B.1 aPol, Mahesh, D.1 aHalder, Priyanka1 aSonavane, Sameer, R.1 aMhaske, Santosh, B.  uhttps://library.ncl.res.in/content/annulation-enals-carbamoylpropiolates-nhc-catalyzed-enolate-pathway-access-functionalized