2985-49-1Relevant academic research and scientific papers
Intermolecular domino Michael/aldol reactions of α,β-unsaturated esters, aromatic aldehydes, and various nucleophiles promoted with a catalytic amount of a guanidine base in DMSO
Matsuo, Jun-ichi,Morita, Shunya,Yoshimura, Tomoyuki
, (2021/07/28)
In DMSO, a catalytic amount of Barton's base (2-t-butyl-1,1,3,3-tetramethylguanidine, BTMG) effectively catalyzed intermolecular three-component reactions of α,β-unsaturated esters, aldehydes, and carbon-, sulfur-, or nitrogen-pronucleophiles to give three-component addition products with the formation of two new σ-bonds: pronucleophiles and aldehydes reacted with α,β-unsaturated esters at their β-positions and α-positions, respectively. Mechanism studies suggested that these reactions proceeded by the first intermolecular Michael addition of anionic nucleophiles that were formed from pronucleophiles with a catalytic amount of BTMG, followed by intermolecular aldol reactions of transient ester enolates even in the presence of more than stoichiometric amounts of acidic pronucleophiles. High nucleophilicity over Br?nsted basicity of transient enolates in polar solvents was observed for transient ester enolates rather than ketone enolates.
Highly convergent straightforward stereoselective synthesis of (+)-C(9a)-epiepiquinamide
Benlahrech, Meriem,Lahosa, Alejandro,Behloul, Cherif,Foubelo, Francisco,Yus, Miguel
, p. 1191 - 1202 (2019/07/31)
– The total synthesis of (+)-C(9a)-epiepiquinamide has been achieved starting from ethyl 5-bromopentanoate, (RS)-tert-butanesulfinamide, nitromethane, ethyl acrylate and acetic anhydride. The diastereoselective coupling of ethyl 4-nitrobutanoate and a chiral N-tert-butanesulfinyl imine, along with a double cyclization involving a primary amine through an intramolecular N-alkylation and lactam formation, are key steps of this synthesis.
CuCN catalyzed one pot synthesis of γ-keto diesters: Domino double Michael addition followed by Nef reaction
Farooq, Saleem,Sangwan, Payare L.,Aleti, Rajeshwar R.,Chinthakindi, Praveen K.,Qurishi, Mushtaq A.,Koul, Surrinder
supporting information; experimental part, p. 3305 - 3309 (2012/08/07)
An efficient one pot synthesis of γ-keto diesters through double Michael addition coupled with Nef reaction in the presence of CuCN catalyst and Cs2CO3 base is described. The reaction proceeds rapidly in DCM to give the products in good yields. A plausible mechanism is proposed.
Base-catalysed intramolecular hydroamination of vinyl sulfiies
Quinet, Coralie,Sampoux, Laetitia,Marko, Istvan E.
supporting information; experimental part, p. 1806 - 1811 (2009/09/06)
Small amounts of n-butyllithium catalyse the highly efficient hydroamination of a large variety of vinyl sulfides. This novel methodology offers an easy access to a wide range of nitrogen heterocycles, including simple pyrrolidines and piperidines, as well as more complex bicyclic compounds. Subsequent transformations of the sulfur group led to the formation of functionalised alkaloid-like substructures. Wiley-VCH Verlag GmbH & Co. KGaA.
Catalysis of the Michael reaction by using natural phosphate doped with potassium fluoride
Sebti, Said,Boukhal, Hassan,Hanafi, Naima,Boulaajaj, Said
, p. 6207 - 6209 (2007/10/03)
The Michael addition of nitroalcanes to α,β-unsaturated carbonyl compounds was carried out at room temperature in ethanol, using natural phosphate doped with potassium fluoride.
