Vinyl Triflimides-A Case of Assisted Vinyl Cation Formation

Area of Science:

• Organic Chemistry
• Supramolecular Chemistry
• Reaction Mechanisms

Background:

• Carbocation-driven reactions often lack selectivity.
• Controlling chemo-, regio-, and stereoselectivity in nucleophilic additions to alkynes remains a challenge.

Purpose of the Study:

• To introduce a new concept for selectivity control in carbocation-driven reactions.
• To achieve selective nucleophile addition to alkynes through vinyl cation formation.
• To develop a general synthetic method for vinyl triflimides.

Main Methods:

• Utilized a lithium (Li+) -based supramolecular framework.
• Performed mechanistic analysis of a model complex (Li2NTf2+ ⋅3H2O).
• Investigated nucleophilic addition to alkynes.

Main Results:

• Achieved chemo-, regio-, and stereoselective addition of nucleophiles to alkynes.
• Demonstrated that complex formation between the nucleophile and the alkyne protonation transition state dictates selectivity.
• Established a simple synthetic procedure for previously inaccessible vinyl triflimides.

Conclusions:

• A Li+-based supramolecular framework effectively controls selectivity in carbocation-driven reactions.
• The mechanism involves specific nucleophile-transition state complexation, leading to selective N-addition to vinyl cations.
• This work provides a versatile synthetic route to vinyl triflimides.