Copper Catalyzed‐TBHP/DTBP Promoted C(sp²)−H Bond Scission of Aldehydes: An Approach to Transform Aldehyde to Esters

Abstract

The direct oxidative C(sp2)−H functionalization represents a step and atom economical approach for the utilization of aldehyde as promising acyl surrogates. A mild and practical copper catalyzed‐TBHP/DTBP promoted esterification of aldehydes in the presence of alkyl halides and alcohols has been developed. This strategy relies on naturally abundant aldehydes as acyl precursors, which can further couple with readily available alkyl halides/alcohols to transform into esters. Preliminary mechanistic investigations reveal that aldehyde in the presence of tert‐butoxy radical transforms into acyl radical. This protocol exhibits a broad substrate scope along with wide functional group compatibility and is applicable to a wide range of aldehydes, including challenging aliphatic aldehydes to undergo the C(sp2)−H bond scission to furnish the desired esters in good to excellent yields.

Unified Approach to Diverse Heterocyclic Synthesis: Organo-Photocatalyzed Carboacylation of Alkenes and Alkynes from Feedstock Aldehydes and Alcohols

“…With this in mind, our lab has been focused on the utilization of feedstock aldehydes as the acyl precursor. ,, We wanted to develop an efficient and diversity-driven approach that can enable the facile construction of functionalized heterocyclic scaffolds that are prevalent in many pharmaceuticals and natural products. Additionally, we wish to utilize alcohols which are even more eco-friendly as acyl handles that have not been employed previously for visible-light-mediated carboacylation.…”

Copper Porphyrin Catalyzed C(sp3)–H Activation via Cross-Dehydrogenative Coupling: Facile Transformation of Aldehydes to Esters

“…In the absence of a catalyst, the target product was not furnished (Table 1, entry 12). Meanwhile, using CuTPP as catalyst, the yield was not obviously improved by adding or reducing the catalyst dosage (Table 1, entries [13][14]. As for oxidant, H2O2, DDQ, Oxone, PhI(OAc)2, m-CPBA and K2S2O8 were also tested which were found to be ineffective for this reaction (Table 1, entries [15][16][17][18][19][20].…”

“…In recent years, the preparation of ester compounds by CDC re-action of aldehydes has also received extensive attentions (Scheme 1, a and b). 12 In this regard, the most successful approach is the direct CDC esterification of aldehydes with C(sp 3 )-H of methyl aromatics, 13 halogenated aromatics, 14 or cyclic ethers. 15 While reports on the CDC preparation of ester compounds using alkanes are less.…”