Iridium-catalyzed alkenyl C-H allylation using conjugated dienes

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• C-H functionalization is a powerful tool for streamlining organic synthesis.
• Developing efficient catalytic systems for C-H allylation remains an active research area.
• Directing group strategies are crucial for regioselective C-H bond activation.

Purpose of the Study:

• To develop an iridium-catalyzed C-H allylation of acrylamides with conjugated dienes.
• To establish a ligand- and additive-free protocol for synthesizing branched 1,4-diene skeletons.
• To demonstrate the broad functional group tolerance and preparative utility of the developed method.

Main Methods:

• Iridium-catalyzed C-H allylation reaction.
• Utilized NH-Ts amide as a directing group.
• Employed conjugated dienes as coupling partners.

Main Results:

• Successfully synthesized branched 1,4-diene skeletons with high efficiency.
• Demonstrated tolerance for various functional groups including OMe, F, Cl, Br, and CF3.
• Showcased preparative scale utility and C-H functionalization of artemisic amide.
• Developed efficient deprotection methods (methylation and hydrolysis) to yield 1,4-dienoic acid.

Conclusions:

• The developed iridium-catalyzed protocol offers a convenient and atom-economic route to valuable branched 1,4-dienes.
• The method exhibits excellent functional group tolerance and broad applicability in organic synthesis.
• The NH-Ts amide directing group facilitates regioselective C-H functionalization and can be readily removed.