3351-78-8Relevant academic research and scientific papers
Reaction of 3-arylidenepropenoic acid derivatives with triethylamine and other amines; Unexpected reductions and vinylogations
Harisha, Attimogae Shivamurthy,Nayak, Suresh Parameshwar,Nagarajan, Kuppuswamy,Row, Tayur Narasingarow Guru,Hosamani, Amar A.
, p. 2880 - 2889 (2016/05/24)
Exposure of ethyl 2-cyano-3-(2-methoxy-5-nitrophenyl)acrylate 1f to triethylamine in hot ethanol resulted in the formation of the dihydro derivative 2f and vinylogue 3f in high yields. Single crystal X-ray data are provided for 3f. Similar reactions were observed for various analogues. The reaction was studied changing aryl substituent, amines and solvents. Pyridyl, thienyl analogues were also examined. The study was extended to cyclic molecules incorporating such systems like thiazolidinedione 8, 3-cyanocoumarin 9 and 4-arylidene-isoquinoline-2,4-diones 11. The last group gave vinylogated products, 4-cinnamylidene-isoquinolinediones and 4-hydroxylated species. A few examples of arylidene derivatives from malononitrile, ethyl acetoacetate, acetyl acetone and ethyl methylsufonylacetate were investigated. Ethyl cinnamate and β-nitrostyrene were unaffected. The reaction is considered to be possibly radical mediated, since addition of free radical quencher suppressed the reaction. Contrary to the effects of thermal conditions, irradiation of 1f in ethanol at 254 and 365 nm gave complex mixtures. A few other interesting observations in this study are noted: vinylogation of 1f with acetaldehyde to 3f; formation of 3f from 1f by the treatment with triethylamine, palladium carbon and reduction of 1f to 2f by triethylammonium formate in DMF.
Applications of caged-designed proton sponges in base-catalyzed transformations Dedicated to Professor Milan Kratochvíl for his 90th birthday anniversary.
Galeta, Juraj,Potá?ek, Milan
, p. 87 - 92 (2014/11/08)
Superbasic properties of caged proton sponges (PSs) - substituted diazatetracyclo[4.4.0.13,10.15,8]dodecanes (DTDs) - were utilized in Knoevenagel and Claisen-Schmidt condensations, the Pudovik reaction, and Michael addition. This investigation covers the influence of the solvent, reaction temperature, catalyst loadings as well as the electronic properties of substituents upon the reaction. Moreover, we provided an activity comparison between our new base and a well-known and commercially available proton sponge (DMAN). The basicity (in MeCN) of our chosen DTD (pKBH+=21.7±0.1) exceeded the prototypal PS - 1,8-bis(dimethylamino)naphthalene (DMAN, pKBH+=18.6), by three orders of magnitude. We proved that DTDs are reasonably active species in monitored reactions, which is a consequence of a hydrogen bridge angle (～130°) between the two nitrogen atoms and the captured proton. We present here syntheses of aminoindolizine, substituted 4H-chromene, and flavanones, and the unexpected formation of a bis-addition product formed after Michael addition, all under mild conditions.
One-pot multistep synthesis of 3-aminoindolizine derivatives
Li, Lianhai,Chua, Waepril Kimberly S.
scheme or table, p. 1392 - 1394 (2011/04/15)
We have developed an efficient one-pot multistep sequence to the synthesis of 3-aminoindolizine derivatives by using Hantzsch ester (9) as a mild hydride transfer agent. The reaction scope was investigated and the effect of substrates on reaction outcomes was discussed.
3-Aminoindolizines
Flitsch, Wilhelm,Kahner-Groene, Sigrid
, p. 871 - 877 (2007/10/02)
3-Aminoindolizines 2, 3 have been obtained from reductions of 2-pyridines 1.A mechanism is proposed for this reaction.
