Allylic Alkylation of Morita-Baylis-Hillman Carbonates with In situ Generated Azomethine Ylides
Li-Wen Shen, Qin Zhao, Lu-Xin Zhou, Hui-Mei Liu, Yun-Qing Jia, Min Xiang, Guang-Wei WangAbstract:
The allylation reaction of Morita-Baylis-Hillman carbonates is an effective method for constructing C-C bonds. Yang's group has utilized azomethine ylides, which are generated in situ from 2-aminomalonate and ortho-amino benzaldehydes, to engage in allylation reactions with MBH carbonates. Despite the initial substrate specificity that confined the reaction to ortho-amino benzaldehydes, rendering benzaldehyde and salicylaldehyde ineffective for producing the desired adducts, our group has made a significant advancement. By employing diethyl amino malonate hydrochloride as the substrate, we have successfully integrated benzaldehyde and salicylaldehyde into this reaction framework, thereby broadening the versatility of the process. This strategy demonstrates excellent substrate tolerance and provides the corresponding adducts with yields up to 99%. The gram-scale synthesis and subsequent product derivatization highlight the significant applicability of this method.
conclusion:
an efficient allylic alkylation between MBH carbonates and azomethine ylides, in suit formed from diethyl aminomalonate hydrochloride and benzaldehyde (salicylaldehydes) was developed. The reaction showed an impressive substrate scope, successfully affording a range of allyl-alkylated products with up to 99% yield.