%0 Journal Article %A Bonne, Damien %A Dekhane, Mouloud %A Zhu, Jieping %D 2004 %T Ammonium Chloride Promoted Ugi Four-Component, Five-Center Reaction of α-Substituted α-Isocyano Acetic Acid:  A Strong Solvent Effect %U https://acs.figshare.com/articles/journal_contribution/Ammonium_Chloride_Promoted_Ugi_Four_Component_Five_Center_Reaction_of_Substituted_Isocyano_Acetic_Acid_A_Strong_Solvent_Effect/3312922 %R 10.1021/ol0479388.s001 %2 https://acs.figshare.com/ndownloader/files/5151652 %K presence %K Strong Solvent Effect Conditions %K diastereomer %K acetic %K ammonium chloride %K acid %K Chloride %K Isocyano %K Ammonium %K reactivity %K Substituted %K 1.5 equiv %K mixture %K aldehyde %K tetrapeptide %K isocyano %K multicomponent synthesis %K derivative %K Promoted %K ratio %K toluene %K Ugi %K amine %K Acetic %K carbonyl compound %K ketone %X Conditions have been developed for the multicomponent synthesis of di- and tetrapeptide (7) based on the unique reactivity of α-isocyano acetic acid (4 and its α -substituted derivatives) by an Ugi four-component, five-center reaction. Simply mixing 4, a carbonyl compound (aldehyde or ketone, 8), and a secondary amine (9) (ratio:  1:1:2) in toluene in the presence of 1.5 equiv of ammonium chloride afforded the desired product in good to excellent yield as a mixture of two diastereomers. %I ACS Publications