Take the direct path: Sequential nucleophilic addition of N‐methoxyamides using DIBAL and organometallic reagents provided substituted N‐methoxyamines in one pot via five‐membered chelated intermediates (see scheme, DIBAL=diisobutylaluminum hydride). The reaction allows functionalization of acyclic amides and macrolactams without a preactivation step, which is generally required for inert amide carbonyl groups.
While the synthesis of amide bonds is now one of the most reliable organic reactions, functionalization of amide carbonyl groups has been a long-standing issue due to their high stability. As an ongoing program aimed at practical transformation of amides, we developed a direct nucleophilic addition to N-alkoxyamides to access multisubstituted amines. The reaction enabled installation of two different functional groups to amide carbonyl groups in one pot. The N-alkoxy group played important roles in this reaction. First, it removed the requirement for an extra preactivation step prior to nucleophilic addition to activate inert amide carbonyl groups. Second, the N-alkoxy group formed a five-membered chelated complex after the first nucleophilic addition, resulting in suppression of an extra addition of the first nucleophile. While diisobutylaluminum hydride (DIBAL-H) and organolithium reagents were suitable as the first nucleophile, allylation, cyanation, and vinylation were possible in the second addition including inter- and intramolecular reactions. The yields were generally high, even in the synthesis of sterically hindered α-trisubstituted amines. The reaction exhibited wide substrate scope, including acyclic amides, five- and six-membered lactams, and macrolactams.
Auf direktem Weg: Sequenzielle nucleophile Additionen an N‐Methoxyamide durch DIBAL und Organometallreagentien ergeben substituierte N‐Methoxyamine (siehe Schema, DIBAL=Diisobutylaluminiumhydrid). Die über Fünfringchelate verlaufenden Eintopfprozesse eröffnen einen Zugang zu funktionalisierten acyclischen Amiden und Makrolactamen ohne den für reationsträge Amid‐Carbonylgruppen sonst nötigen zusätzlichen Aktivierungsschritt.
Three-component allylation and cyanation utilizing a ketone and an N-methoxyamine are reported. The high nucleophilicity of the N-methoxyamine and high electrophilicity of the corresponding iminium ion enable the concise synthesis of α-trisubstituted amines in a single step.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.