Organocatalytic Sequential One-Pot Double Cascade Asymmetric Synthesis of Wieland−Miescher Ketone Analogues from a Knoevenagel/Hydrogenation/Robinson Annulation Sequence: Scope and Applications of Organocatalytic Biomimetic Reductions
作者:Dhevalapally B. Ramachary、Mamillapalli Kishor
DOI:10.1021/jo070277i
日期:2007.7.1
practical and novel organocatalytic chemo- and enantioselective process for the cascade synthesis of highly substituted 2-alkyl-cyclohexane-1,3-diones and Wieland−Miescher (W−M) ketone analogs is presented via reductive alkylation as a key step. First time, we developed the one-step alkylation of dimedone and 1,3-cyclohexanedione with aldehydes and Hantzsch ester through an organocatalytic reductive alkylation
Evaluation of sodium acetate trihydrate–urea DES as a benign reaction media for the Biginelli reaction. Unexpected synthesis of methylenebis(3-hydroxy-5,5-dimethylcyclohex-2-enones), hexahydroxanthene-1,8-diones and hexahydroacridine-1,8-diones
作者:Camilo A. Navarro、Cesar A. Sierra、Cristian Ochoa-Puentes
DOI:10.1039/c6ra13848a
日期:——
In this work, the low melting mixture sodium acetate trihydrate–urea was synthesized and the eutectic composition was determined and characterized. The performance of this deep eutectic solvent on the Biginelli reaction was evaluated.
Chickpea leaf exudates (CLE) mediated Knoevenagel–Michael reactions for the synthesis of diketodiols and biscoumarins
作者:Rupesh C. Patil、Dnyandev N. Zambare、Shashikant A. Damate、Ashutosh A. Jagdale、Snehali R. Mali、Sachinkumar K. Shinde、Suresh S. Patil
DOI:10.1007/s11164-022-04707-8
日期:2022.5
A green, highly efficient, and eco-friendly protocol for Knoevenagel–Michael addition reaction is reported in Chickpea leaf exudates (CLE) as a naturally sourced biosurfactant. The reactions between dimedone/4-hydroxycoumarins and a variety of aryl aldehydes were carried out in presence of CLE to afford diketodiols/biscoumarins. The synthetic pathway complies with several key requirements of green chemistry principles such as the employment of natural feedstock as green reaction media, ambient temperature, atom economy along with natural biosurfactant type Bronsted acids, and recyclable and biodegradable catalyst which led to a 28-fold increase in molar efficiency versus industrial standard protocols. Its dynamic phase is confirmed by the optical microscopy technique and critical micelle concentration measurement. The notable advantages of the present protocol were simple work-up procedure, high yield within short reaction time, easy separation of products, avoiding tedious column chromatography thus making the protocol environmentally friendly, sustainable, and economical.
The reaction of imines 1 with 5,5-dimethyl-1,3-cyclohexandione 2 in methanol was investigated. When the reaction was carried out without a catalytic amount of molecular iodine, ring-opening derivatives of xanthenediones 3 were obtained in high yields. On the other hand, when molecular iodine and a catalytic amount of zinc powder were employed as the catalyst, xanthenediones derivatives 4 were obtained with excellent yields.
Samanta, Swati; Das Gupta, Arpita; Mondal, Rina, Journal of the Indian Chemical Society, 2013, vol. 90, # 6, p. 845 - 852