18437-68-8Relevant articles and documents
Chiral Phosphoric Acid Catalyzed Asymmetric Desymmetrization of para-Quinamines with Isocyanates: Access to Functionalized Imidazolidin-2-one Derivatives
Hu, Kai-Wen,You, Xiao,Wang, Jin-Zheng,Wen, Xiaoan,Sun, Hongbin,Xu, Qing-Long,Lai, Zengwei
supporting information, p. 7873 - 7877 (2021/10/20)
The development of enantioselective desymmetrization of para-quinamines with isocyanates catalyzed by chiral phosphoric acid is reported. The strategy provides concise access to functionalized imidazolidin-2-one derivatives in high yields and enantioselectivities under mild reaction conditions. Remarkably, this reaction could be performed on a gram scale using 5 mol % catalyst loading and the chiral imidazolidin-2-one derivatives could be easily transformed into valuable scaffolds without disturbing the enantiopurity, demonstrating the synthetic utility of this protocol.
Sulfated tungstate: A highly efficient, recyclable and ecofriendly catalyst for chemoselective N-tert butyloxycarbonylation of amines under the solvent-free conditions
Ingale, Ajit P.,Shinde, Sandeep V.,Thorat, Nitin M.
supporting information, p. 2528 - 2543 (2021/07/02)
Sulfated tungstate catalyzed an efficient and ecofriendly protocol has been described for the chemoselective N-tert-butyloxycarbonylation of amines under the solvent-free conditions at room temperature. The variety of functionalized aliphatic, aromatic and heteroaromatic amines efficiently undergoes the N-tert-butyloxycarbonylation under the developed protocol. The aminoalcohol, aminophenol, aminoester as well as various chiral amines underwent the chemoselective N-Boc protection under the optimized reaction condition. The rapid reaction rate, mild conditions, very good functional group tolerance, excellent yield, solvent-free, easy recovery products and excellent catalyst recyclability are the advantages of this protocol. This makes the protocol feasible, economical and environmentally benign.
Base-Mediated Generation of Ketenimines from Ynamides: [3+2] Annulation with Azaallyl Anions
D'Hollander, Agathe C. A.,Romero, Eugénie,Vijayakumar, Kamsana,Le Houérou, Camille,Retailleau, Pascal,Dodd, Robert H.,Iorga, Bogdan I.,Cariou, Kevin
supporting information, p. 2903 - 2908 (2021/04/21)
Under basic conditions and heat, ynamides can serve as precursors to ketenimines, whose synthetic potential is often hampered by their difficulty of access. Herein, we report that they can undergo a [3+2] cycloaddition with 2-azaallyl anions, obtained from benzylimines under the same reaction conditions. This reaction between two highly reactive intermediates, both generated in situ from bench stable starting materials, gives access to various nitrogen-rich heterocycles. The reaction usually proceeds with excellent diastereoselectivity, in favor of the cis adduct. Deuteration experiments and DFT calculations helped rationalize the regio- and stereoselectivity of the process as well as the formation of side products. (Figure presented.).