16892-25-4Relevant academic research and scientific papers
KOtBu-Catalyzed Michael Addition Reactions Under Mild and Solvent-Free Conditions
Thiyagarajan, Subramanian,Krishnakumar, Varadhan,Gunanathan, Chidambaram
, p. 518 - 523 (2020)
Designed transition metal complexes predominantly catalyze Michael addition reactions. Inorganic and organic base-catalyzed Michael addition reactions have been reported. However, known base-catalyzed reactions suffer from the requirement of solvents, additives, high pressure and also side-reactions. Herein, we demonstrate a mild and environmentally friendly strategy of readily available KOtBu-catalyzed Michael addition reactions. This simple inorganic base efficiently catalyzes the Michael addition of underexplored acrylonitriles, esters and amides with (oxa-, aza-, and thia-) heteroatom nucleophiles. This catalytic process proceeds under solvent-free conditions and at room temperature. Notably, this protocol offers an easy operational procedure, broad substrate scope with excellent selectivity, reaction scalability and excellent TON (>9900). Preliminary mechanistic studies revealed that the reaction follows an ionic mechanism. Formal synthesis of promazine is demonstrated using this catalytic protocol.
Synthesis and fluorescence studies on menthol-coumarin conjugates
Rao, H. Surya Prakash,Desai, Avinash
, p. 514 - 524 (2015/07/07)
A three-step protocol for synthesis of alcohol containing aliphatic natural products and coumarins has been described. The Blaise reaction of converting the nitrile to β-keto esters formed key-step in this protocol. The menthol-coumarin conjugates prepared for the first time are subjected to absorption and fluorescence emission studies. The studies reveal that menthol substitution has little influence on the absorption or emission characteristic of the chromophore. However, substitution of C(6)H or C(6)OMe of the coumarin with NEt2 has dramatic influence on both absorption and emission of the conjugate. Solvatochromic studies and analysis of Stoke shift data show that the menthol-coumarin conjugate with C(6)NEt2 stabilizes itself in dipolar push-pull structure in ground and excited states.
