Selective functionalization of sp(3) C-H bonds adjacent to nitrogen using (diacetoxyiodo)benzene (DIB)

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Catalysis

Background:

• Selective functionalization of C-H bonds is crucial in organic synthesis.
• Nitrogen-containing heterocycles are important structural motifs in pharmaceuticals and natural products.
• Developing efficient methods for modifying these structures is an ongoing challenge.

Purpose of the Study:

• To report a novel PhI(OAc)(2)-mediated method for selective functionalization of sp(3) C-H bonds adjacent to nitrogen atoms.
• To explore the scope and limitations of this reaction with different nitrogen-containing substrates.
• To demonstrate the utility of this method in synthesizing complex molecules.

Main Methods:

• Utilized phenyliodine(III) diacetate (PhI(OAc)(2)) as the key reagent for C-H bond functionalization.
• Investigated the reaction with piperidine and tetrahydroisoquinoline derivatives.
• Explored the coupling of amines with active methylene compounds like nitroalkanes, malonates, and beta-keto esters.

Main Results:

• Achieved direct cis-2,3-diacetoxylation of piperidine derivatives at alpha and beta positions relative to the nitrogen atom.
• Obtained various alpha-C-H functionalized products from tetrahydroisoquinoline derivatives.
• Successfully synthesized alpha-amino nitriles via oxidative coupling of amines with malononitrile.

Conclusions:

• The developed PhI(OAc)(2)-mediated reaction offers a selective and efficient route for functionalizing sp(3) C-H bonds adjacent to nitrogen.
• This methodology provides access to diverse functionalized nitrogen heterocycles and alpha-amino nitriles.
• The reaction's broad substrate scope and mild conditions make it a valuable tool in synthetic organic chemistry.