The present invention relates to a compound of formula I
wherein R
1
, R
2
, and Ar are as defined herein or to a pharmaceutically acceptable acid addition salt, to a racemic mixture, or to its corresponding enantiomer and/or optical isomer thereof. These compounds and their pharmaceutical compositions are useful in the treatment of neurological and neuropsychiatric disorders.
resulting from this process are obtained in high yields and are analytically pure, i.e., they do not require distillation or further purification, which is a comfortable improvement of the ancestral VictorMeyer reaction.
L-tert-Leucine derived urea-ammonium salts: Efficient bifunctional phase transfer catalysts for highly diastereo- and enantioselective aza-Henry reaction of isatin-derived N-Boc ketimines with α-aryl nitromethanes
efficient way of aza-Henry reaction between isatin-derived N-Boc ketimines and α-aryl nitromethanes catalyzed by bifunctional phase transfer catalysts with a quaternary ammonium center derived from L-tert-Leucine has been developed. A series of 3-substituted 3-amino-oxindoles were constructed by this catalytic protocol in excellent yields (90–99%), with high enantioselectivities (83–95%) and diastereoselectivities
A highly stereoselective aza‐Henryreaction of α‐aryl nitromethanes with aromatic N‐Boc imines was established by using C1‐symmetric chiral ammonium betaine as a bifunctional organic base catalyst. Various substituted aryl groups for both imines and nitromethanes were tolerated in the reaction, and a series of precursors for the synthesis of unsymmetrical anti‐1,2‐diaryl ethylenediamines was provided
A high-yield, highly diastereo- and enantioselective nitro-Mannich reaction of α-aryl nitromethanes with amidosulfones catalyzed by a novel chiral phase-transfercatalyst, bearing multiple H-bonding donors, derived from quinine was developed. A variety of α-aryl nitromethanes and amidosulfones were investigated; and the corresponding products were obtained in excellent yields with excellent diastereo-