479191-62-3Relevant academic research and scientific papers
Access to Spirocyclic Benzothiophenones with Multiple Stereocenters via an Organocatalytic Cascade Reaction
Formánek, Bed?ich,Tauchman, Ji?í,Císa?ová, Ivana,Vesely, Jan
, p. 8510 - 8521 (2020/07/16)
The present report describes an organocatalytic cascade reaction between 2-alkylidene benzo[b]thiophenone derivatives and enones in the presence of the Cinchona alkaloid amine. Spirobenzothiophenonic cyclohexane derivatives containing three stereocenters were prepared via one-step synthesis in yields ranging from 88 to 96% and in enantioselectivities (enantiomeric excess (ee)) ranging from 85 to 97%, with diastereoselectivities of approximately 14/2/1. Therefore, this method provides an efficient route for the synthesis of a new class of optically active 2-spirobenzothiophenones.
Highly enantioselective epoxidation of α,β-unsaturated ketones catalyzed by primary-secondary diamines
Lu, Yingpeng,Zheng, Changwu,Yang, Yingquan,Zhao, Gang,Zou, Gang
supporting information; experimental part, p. 3129 - 3133 (2012/01/03)
The asymmetric epoxidation of α,β-unsaturated ketones has been achieved by using functional and readily accessible primary-secondary diamines as the catalysts, giving the useful alkyl epoxy products with good yields and high enantioselectivities (up to 99% ee). Copyright
One-pot synthesis of imidazolines from aldehydes: detailed study about solvents and substrates
Fujioka, Hiromichi,Murai, Kenichi,Kubo, Ozora,Ohba, Yusuke,Kita, Yasuyuki
, p. 638 - 643 (2007/10/03)
Imidazolines were prepared in one-pot operation from aldehydes and diamines through oxidation of aminal intermediates by NBS. This method could be applied to various aromatic and aliphatic aldehydes and N-nonsubstituted and N-monosubstituted 1,2-diamines. Furthermore, it was found that CH2Cl2 could be altered to TBME, a more environmentally friendly solvent, in the reaction using N-nonsubstituted 1,2-diamines. The reaction conditions were very mild and chemoselective.
Novel syntheses of enantiopure hexahydroimidazo[1,5-b]isoquinolines and tetrahydroimidazo[1,5-b]isoquinolin-1(5H)-ones via iminium cation cyclizations
Katritzky, Alan R.,Suzuki, Kazuyuki,He, Hai-Ying
, p. 8224 - 8229 (2007/10/03)
Condensations of chiral diamines 11a-c with benzotriazole and formaldehyde gave benzotriazolyl intermediates 12a-c; similar condensations of α-amino-amides 10a-c with benzotriazole and paraformaldehyde gave 14a-c. Subsequent treatment of 12a-c and 14a-c with AlCl3 led to enantiopure tricyclic 1,2,3,5,10,10a-hexahydroimidazo[1,5-b]isoquinolines 1a-c and 2,3,10,10a-tetrahydroimidazo[1,5-b]isoquinolin-1(5H)-ones 15a-c, respectively, via Lewis acid promoted iminium cation cyclizations.
