40888-66-2Relevant articles and documents
A facile, efficient and solvent-free titanium (IV) ethoxide catalysed knoevenagel condensation of aldehydes and active methylenes
Ramaiah, Manjunatha M.,Shivananju, Nanjunda Swamy,Shubha, Priya Babu
, p. 107 - 115 (2020/02/04)
Titanium ethoxide has been employed as a novel and efficient reagent for the Knoevenagel condensation of aldehydes with active methylenes such as diethyl malonate and ethyl cyanoacetate under solvent free conditions to afford substituted olefins in high to excellent yields. The reaction is suitable for a variety of aromatic, aliphatic and heteroaromatic aldehydes with various active methylenes. Parallel to this, microwave irradiation has been utilized to achieve improved reaction rates and enhanced yields. Herein, we illustrated a convenient method for the preparation of α,β-unsaturated compounds using both conventional and microwave irradiation methods. An efficient and solvent free Knoevenagel condensation between aldehydes and active methylenes was developed using titanium ethoxide. The procedure proved to be successful with a wide range of substrates such as aromatic, aliphatic and heterocyclic aldehydes and various active methylenes to afford substituted olefins. The reaction was also carried out under microwave irradiation to accomplish the corresponding olefins with improved reaction rates, yields and cleaner reaction profiles.We have developed an efficient and novel methodology for the synthesis of olefinic compounds by Knoevenagel condensation under solvent-free conditions using titanium ethoxide, for the first time, as a reagent as well as a solvent. This method is appropriate for the synthesis of a variety of aromatic aldehydes containing various electron-donating and withdrawing groups, aliphatic and heteroaromatic aldehydes. The significant advantages offered by this methodology could be applied to various active methylenes in order to offer the corresponding Knoevenagel products. Thus, we believe that this method delivers high conversions, cleaner reaction profiles under solvent-free reaction conditions and shorter reaction times, all of which make it a very useful and attractive approach for the preparation of a wide range of substituted olefins.
A Regioselective Metal-Free Construction of 3-Aroyl Coumarins by Csp2-H Functionalization
Jafarpour, Farnaz,Abbasnia, Masoumeh
, p. 11982 - 11986 (2016/12/09)
A successive metal-free TBHP-mediated regioselective C-H functionalization of coumarins toward expedient synthesis of 3-aroyl coumarins is unveiled. The ongoing method conducted through the reaction of either coumarins or coumarin-3-carboxylic acids with
Regioselective Coupling Reactions of Coumarins with Aldehydes or Di-tert-butyl Peroxide (DTBP) through a C(sp2)-H Functionalization Process
Zhao, Wannian,Xu, Lei,Ding, Yingcai,Niu, Ben,Xie, Ping,Bian, Zhaogang,Zhang, Denghong,Zhou, Aihua
, p. 325 - 330 (2016/02/14)
Coumarin derivatives are highly valuable compounds in drug discovery. Herein, we have developed two new coupling reactions that involve coumarins and either aldehydes or di-tert-butyl peroxide (DTBP) in the presence of inexpensive copper or iron catalysts. Both of these reactions proceed through a C(sp2)-H functionalization process to regioselectivity generate keto- or methyl-substituted coumarin derivatives in moderate to good yields These coupling reactions will enrich current coumarin chemistry.
