572-60-1Relevant articles and documents
Nickel-Catalyzed Dehydrogenation of N-Heterocycles Using Molecular Oxygen
Banerjee, Debasis,Bera, Atanu,Bera, Sourajit
supporting information, (2020/09/02)
Herein, an efficient and selective nickel-catalyzed dehydrogenation of five- and six-membered N-heterocycles is presented. The transformation occurs in the presence of alkyl, alkoxy, chloro, free hydroxyl and primary amine, internal and terminal olefin, trifluoromethyl, and ester functional groups. Synthesis of an important ligand and the antimalarial drug quinine is demonstrated. Mechanistic studies revealed that the cyclic imine serves as the key intermediate for this stepwise transformation.
Anti-Selective Asymmetric Nitro-Michael Reaction of Furanones: Diastereocontrol by Catalyst
Sekikawa, Tohru,Kitaguchi, Takayuki,Kitaura, Hayato,Minami, Tatsuya,Hatanaka, Yasuo
supporting information, p. 646 - 649 (2016/03/01)
Catalyst-controlled switching of diastereoselectivity from high syn-selectivity (>98/2 dr, syn) to anti-selectivity (up to 96/4 dr, anti) of the asymmetric nitro-Michael reaction of furanones is described. Anti-diastereoselectivity of the nitro-Michael reaction is very rare. With 0.1-5 mol % loadings of an epi-quinine catalyst, the reaction of 5-substituted 2(3H)-furanones with nitroalkenes smoothly proceeded to give the anti-Michael adducts in good yields (up to 95%) with excellent diastereo- and enantioselectivities (up to 96/4 dr, anti; up to 99% ee). DFT calculations support a model that accounts the high anti-diastereoselectivity. (Chemical Equation Presented).
An easy route to exotic 9-epimers of 9-amino-(9-deoxy) cinchona alkaloids with (8S, 9R) and (8R, 9S)-configurations through two inversions of configuration
Wan, Jing-Wei,Ma, Xue-Bing,He, Rong-Xing,Li, Ming
, p. 557 - 560 (2014/05/06)
Four exotic chiral organocatalysts, 9-amino-(9-deoxy) cinchona alkaloids with (8S, 9R) and (8R, 9S)-configurations, were conveniently synthesized for the first time in 27-72% total yields through two conversions of configuration at the 9-stereogenic centers of commercially available cinchona alkaloids.