Facile synthesis of fused 1,2,3-triazoles by a proline-catalyzedreaction of an azido aldehyde and a nitroalkane is elaborated. The present tandem protocol proceeds via an organocatalytic Knoevenagelcondensation of the azido aldehyde and nitroalkane followed by intramolecular azide–nitroalkene cycloaddition. The functionalized bicyclic triazole is obtained by elimination of HNO2 from the cycloadduct
development of expeditious methods to synthesize these skeletons remains a challenging task. In this work, the catalyticcyclization of biomass-derived 2-furylcarbinols with an azide to form fused triazoles is described. This approach takes advantage of a single catalyst Yb(OTf)3 and operates via a furfuryl-cation-induced intramolecular [3 + 2] cycloaddition/furan ring-opening cascade.
Facile Procedure for Generating Side Chain Functionalized Poly(α-hydroxy acid) Copolymers from Aldehydes via a Versatile Passerini-Type Condensation
作者:Mark Rubinshtein、Carrie R. James、Jennifer L. Young、Yanyan J. Ma、Yoshihisa Kobayashi、Nathan C. Gianneschi、Jerry Yang
DOI:10.1021/ol101433v
日期:2010.8.6
synthesizing α-hydroxy N-acylindoles in one-pot via an acid-catalyzed condensation of a convertible isonitrile with water and various aldehydes is presented. These intermediates were incorporated into poly(α-hydroxyacid) copolymers bearing residues with functionalizable side chains, which could be further modified through Cu(I)-catalyzed azide−alkyne cylcoaddition reactions. This versatile synthetic
Synthesis of Enantiomerically Pure Isoxazolidine Monomers for the Preparation of<i>β</i><sup>3</sup>-Oligopeptides by Iterative<i>α</i>-Keto AcidHydroxylamine (KAHA) Ligations
作者:Ying-Ling Chiang、Justin A. Russak、Nancy Carrillo、Jeffrey W. Bode
DOI:10.1002/hlca.201200484
日期:2012.12
for the synthesis of enantiomerically pure isoxazolidine monomers for the synthesis of β3‐oligopeptides via α‐keto acidhydroxylamine (KAHA) ligation is presented. This one‐pot synthetic method utilizes in situ generated nitrones bearing gulose‐derived chiral auxiliaries for the asymmetric 1,3‐dipolar cycloaddition with methyl 2‐methoxyacrylate. The resulting enantiomerically pure isoxazolidine monomers