[3 + 2] Cycloadditions of Tertiary Amine N-Oxides and Silyl Imines as an Innovative Route to 1,2-Diamines

Abstract

We have developed a one-pot synthetic method for producing 1,2-diamines from easily prepared and commercially available precursors through a formal umpolung process. Our method utilizes an efficient [3 + 2] cycloaddition as the key step in forming substituted 1,2-diamines in moderate to high yields. These resulting compounds can undergo subsequent transformations, demonstrating their utility as synthetic building blocks for more complex scaffolds. Finally, we propose a reasonable mechanism for this transformation using density functional theory modeling, justifying the experimental observations.

Diastereoselective [3 + 2] Cycloaddition between Tertiary Amine N-Oxides and Substituted Alkenes to Access 7-Azanorbornanes

“…The mechanism of this reaction is expected to be analogous to our previous studies with generation of an azomethine ylide. , Of greater interest to this work was an explanation for the diastereotopic selectivity for the endo product. We postulate that this is due to steric considerations since we saw a universal increase in d.r.…”

“…The use of tertiary amine N -oxides as precursors for [3 + 2] cycloadditions was originally reported by Roussi where they demonstrated the formation of various pyrrolidines. − Later work by Davoren expanded this area through use of various stilbenes . Previously, we probed this chemistry computationally and established a synthetic method producing 1,2-diamines and imidazolidines by coupling tertiary amine N -oxides with silyl imines . We present here our most recent studies into the reaction of pyrrolidine N -oxides with substituted alkenes to give endo -7-azanorbornanes in good yields and high diastereoselectivities.…”

Ring Opening of Aziridines by Pendant Sulfamates Allows for Regioselective and Stereospecific Preparation of Vicinal Diamines

“…Vicinal diamines (1,2-diamines) are well represented in molecules of value, including those used as medicines, ligands, and agrochemicals. − Given their importance to multiple areas of synthetic chemistry, it is no surprise that numerous protocols have been invented for their construction. − Diamination of olefins − and untethered (intermolecular) aminolysis − of aziridines are common strategies for accessing these motifs (Scheme ). The direct diamination of olefins is a powerful approach for the construction of vicinal diamines as it installs both nitrogens in a single synthetic step; some limitations of existing protocols include harsh reaction conditions, limited substrate scope, and issues with regioselectivity and stereoselectivity.…”