Direct esterification of allylic C(sp³)–H via iron nanoparticle–loaded kaolin-catalyzed cross dehydrogenative coupling

ABSTRACT

Iron is the most abundant transition metal on Earth. In this study, we have demonstrated an iron nanoparticle–loaded kaolin-catalyzed cross dehydrogenative coupling (CDC) reaction via C(sp³)–H activation. We use CDC of carboxylic acids with cyclohexenes to discuss various reaction parameters such as the amount of catalyst, oxidant, reaction temperature, and time. Under optimized reaction condition, the corresponding allylic ester was obtained with good yield of (85%). Screening of substituted benzoic acids and cyclic and acyclic olefins shows broad catalytic activities. Notably, the catalyst can be easily separated from the reaction mixture via simple centrifugation and remains active over five cycles of reuse.

GRAPHICAL ABSTRACT

KEYWORDS:

• Iron nanoparticle-loaded kaolin
• heterogeneous catalytic activity
• C(sp3)-H activation
• CDC reaction
• recyclable

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supporting information

Details of the experimental section, particle characterization, and ¹H and ¹³C NMR spectra are given in the Supporting information.

Additional information

Funding

This research was financially supported by the National Science Foundation of China [grant no 22061034], the Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region [grant no NMGIRT2302], and the Collaborative Innovation Center for Water Environmental Security of Inner Mongolia Autonomous Region [grant no XTCX003]