14479-58-4Relevant academic research and scientific papers
5-arylidene derivatives of meldrum's acid as synthons in pyrano[4,3-b]pyran synthesis
Palasz, Aleksandra,Jelska, Katarzyna,Ozog, Monika,Serda, Pawel
, p. 481 - 488 (2007)
The reactions of 5-arylidene derivatives of Meldrum's acid with ethyl vinyl ether or N-vinyl-2-oxazolidinone yielded trans-trans-(2,4:4,7)-pyrano[4,3-b] pyrans, cis-trans-(2,4:4,7)-pyrano[4,3-b]pyrans, or diastereoisomeric mixtures of pyrano[4,3-b]pyrans
trans-Selective hydrocyanation of ynoates, ynones and ynoic acids catalyzed by nucleophilic phosphines
Sch?mberg, Fritz,Peri?, Milica,Meyer, Maximilian,Vilotijevi?, Ivan
, (2021/10/04)
trans-Selective hydrocyanation of ynoates and ynones in the presence of TMSCN and an alcohol additive are catalyzed by nucleophilic phosphines. The trisubstituted E-olefin products of anti-addition of hydrogen cyanide to the alkyne are produced with high regio- and stereoselectivity. The alcohol additive reacts with TMSCN to produce hydrogen cyanide in situ. Ynoic acids undergo the phosphine catalyzed hydrocyanation in the presence of TMSCN under aprotic conditions only. In these reactions, TMSCN reacts with the acid to generate hydrogen cyanide and the silyl ester which, unlike the acid, undergoes phosphine catalyzed hydrocyanation and gives the stereo-defined E-2-cyano-acrylic acids after work up.
Synthesis of (E)-α,β-unsaturated carboxylic esters derivatives from cyanoacetic acid via promiscuous enzyme-promoted cascade esterification/Knoevenagel reaction
Wilk, Monika,Trzepizur, Damian,Koszelewski, Dominik,Brodzka, Anna,Ostaszewski, Ryszard
, (2019/02/25)
A new enzymatic protocol based on lipase-catalyzed cascade toward (E)-α,β-unsaturated carboxylic esters is presented. The proposed methodology consists of elementary organic processes starting from acetals and cyanoacetic acid leading to the formation of desired products in a cascade sequence. The combination of enzyme promiscuous abilities gives a new opportunity to synthesize complex molecules in the one-pot procedure. Results of studies on the influence of an enzyme type, solvent, and temperature on the cascade reaction course are reported. The presented methodology provides meaningful qualities such as significantly simplified process, excellent E-selectivity of obtained products and recycling of a biocatalyst.
Aza-Wittig Reaction with Nitriles: How Carbonyl Function Switches from Reacting to Activating
Tukhtaev, Hamidulla B.,Ivanov, Konstantin L.,Bezzubov, Stanislav I.,Cheshkov, Dmitry A.,Melnikov, Mikhail Ya.,Budynina, Ekaterina M.
supporting information, p. 1087 - 1092 (2019/02/19)
Transformations of α-EWG-substituted (electron-withdrawing group, EWG) γ-azidobutyronitriles proceeding via unusual aza-Wittig reactions between the phosphazene and nitrile functions and affording pyrrole-derived iminophosphazenes were developed. α-EWGs w
Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water
Xu, Hao,Pan, Liyang,Fang, Xiaomin,Liu, Baoying,Zhang, Wenkai,Lu, Minghua,Xu, Yuanqing,Ding, Tao,Chang, Haibo
supporting information, p. 2360 - 2365 (2017/05/29)
A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.
A convenient synthesis of pyrimidinone and pyrimidine containing bisheteroarenes and analogs
Maurya, Hardesh K.,Gupta, Atul
, p. 22106 - 22114 (2014/06/23)
The synthesis of pyrimidinone containing bisheteroarenes (3) and related analogs (9 and 10) by the reaction of active methylenes or substituted methyl acrylate with nitrogen containing precursors viz. amidines, or thiourea in water as well as other organic solvents was studied. Synthesized compounds have further been explored for the synthesis of diversified pyrimidines 4, 6-8, 11, 12 and 14 through a sequential approach. This journal is the Partner Organisations 2014.
Sevelamer as an efficient and reusable heterogeneous catalyst for the Knoevenagel reaction in water
Zhao, Xian-Liang,Yang, Ke-Fang,Zhang, Yan-Ping,Zhu, Ju,Xu, Li-Wen
supporting information, p. 1141 - 1144 (2014/08/18)
A catalyst system of Sevelamer, a phosphate-binding drug, has been prepared and used in the Knoevenagel reaction of aromatic aldehydes in water to produce substituted electrophilic alkenes. The products were obtained in excellent yields. Several novel, re
Versatile CuI/Pd0 dual catalysis for the synthesis of quaternary α-allylated carbonyl compounds: Development, mechanistic investigations and scope
Nahra, Fady,Mace, Yohan,Boreux, Arnaud,Billard, Francois,Riant, Olivier
supporting information, p. 10970 - 10981 (2014/09/17)
We report herein a versatile cooperative dual catalysis reaction based on a CuI/Pd0 system. Mechanistic investigation shows that every component plays a crucial role in determining the reaction outcome. The reaction is successfully extended to various substrates; such as α,β-unsaturated ketones, malonates and coumarins. The strategy tolerates different substitution patterns and affords good yields for each family of substrates.
Synthetic and mechanistic studies of metal-free transfer hydrogenations applying polarized olefins as hydrogen acceptors and amine borane adducts as hydrogen donors
Yang, Xianghua,Fox, Thomas,Berke, Heinz
experimental part, p. 852 - 860 (2012/02/05)
Metal-free transfer hydrogenation of polarized olefins (RR′ CCEE′: R, R′ = H or organyl, E, E′ = CN or CO2Me) using amine borane adducts RR′NH-BH3 (R = R′ = H, AB; R = Me, R′ = H, MAB; R = tBu, R′ = H, tBAB; R = R′ = Me, DMAB) as hydrogen donors, were studied by means of in situ NMR spectroscopy. Deuterium kinetic isotope effects and the traced hydroboration intermediate revealed that the double H transfer process occurred regio-specifically in two steps with hydride before proton transfer characteristics. Studies on substituent effects and Hammett correlation indicated that the rate determining step of the HN transfer is in agreement with a concerted transition state. The very reactive intermediate [NH2BH2] generated from AB was trapped by addition of cyclohexene into the reaction mixture forming Cy2BNH2. The final product borazine (BHNH)3 is assumed to be formed by dehydrocoupling of [NH2BH2] or its solvent stabilized derivative [NH2BH2]-(solvent), rather than by dehydrogenation of cyclotriborazane (BH2NH 2)3 which is the trimerization product of [NH 2BH2].
Synthesis of dihydrouracils spiro-fused to pyrrolidines: Druglike molecules based on the 2-arylethyl amine scaffold
Blanco-Ania, Daniel,Valderas-Cortina, Carolina,Hermkens, Pedro H.H.,Sliedregt, Leo A.J.M.,Scheeren, Hans W.,Rutjes, Floris P.J.T.
experimental part, p. 2269 - 2301 (2010/07/15)
The synthesis of a small library of dihydrouracils spiro-fused to pyrrolidines is described. These compounds are synthesized from ss-aryl pyrrolidines, providing products with the 2-arylethyl amine moiety, a structural feature often encountered in compounds active in the central nervous system. The ss-aryl pyrrolidines are synthesized through a three-step methodology that includes a Knoevenagel condensation reaction, a 1,3-dipolar cycloaddition reaction, and a nitrile reduction. Copyright
