MCM-41-SO 3 H, ordered mesoporous silica material MCM-41 with covalently anchored sulfonic acid groups, was used as a solid acid catalyst for the convenient, efficient, and ‘green’ synthesis of 2-amino-6-(hydroxymethyl)-8-oxo-4-aryl-4,8-dihydropyrano[3,2- b ]pyrans via a one-pot, three-component reaction of 5-hydroxy-2-(hydroxymethyl)-4 H -pyran-4-one, aldehydes and malononitrile in aqueous media.
The first efficient biocatalytic route for the synthesis of Kojic acid derivatives in aqueous media
作者:Kiran S. Dalal、Mangal A. Chaudhari、Dipak S. Dalal、Bhushan L. Chaudhari
DOI:10.1016/j.catcom.2021.106289
日期:2021.4
The first efficient biocatalytic route for the synthesis of kojic acidderivatives was developed in presence of an enzyme. In this process, benzaldehydes, malononitrile and kojic acid were used as starting materials while lipase from Aspergillus niger was the promiscuous biocatalyst giving high conversion (82–95%) of kojic acidderivatives in aqueous medium. The probable enzymatic mechanism is proposed
Sonochemistry in an organocatalytic domino reaction: an expedient multicomponent access to structurally functionalized dihydropyrano[3,2-<i>b</i>]pyrans, spiro-pyrano[3,2-<i>b</i>]pyrans, and spiro-indenoquinoxaline-pyranopyrans under ambient conditions
irradiation in aqueous ethanolic solution at ambient temperature has been developed. This methodology can involve the assembly of C-C, C[double bond, length as m-dash]C, C-O, C-N bonds via a one-pot operation, and following this protocol, a series of novel amino-substituted spiro[indeno[1,2-b]quinoxaline-11,4-pyrano[3,2-b]pyran]-3-carbonitrile/carboxylates have been synthesized. The practical utility of