title: On-Resin Conjugation of Diene-Polyamides and Maleimides via Diels-Alder Cycloaddition.
abstract: The reaction between maleimides and resin-linked diene-polyamides allows the latter to be used in the preparation of conjugates. Conjugation takes place by reacting the insoluble, hydrophobic diene component either with water-soluble dienophiles or with dienophiles requiring mixtures of water and organic solvents. Experimental conditions can be adjusted to furnish the target conjugate in good yield with no need of adding large excesses of soluble reagent. In case protected maleimides are used, maleimide deprotection and Diels-Alder cycloaddition can be simultaneously carried out to render conjugates with different linking positions. On-resin conjugation is followed by an acidic treatment that removes the polyamide protecting groups with no harm to the cycloadduct, in contrast with the unreacted diene that is indeed degraded under these conditions. Cycloadducts incorporating suitable functional groups can undergo subsequent additional conjugation reactions in solution to furnish double conjugates.
authors.affiliation: Departament de Química Orgànica, Facultat de Química and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
authors.forename: Omar
authors.initials: O
authors.lastname: Brun
authors.affiliation: Departament de Química Orgànica, Facultat de Química and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Elduque
authors.affiliation: Departament de Química Orgànica, Facultat de Química and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Pedroso
authors.affiliation: Departament de Química Orgànica, Facultat de Química and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Grandas
mesh_terms: D001686:Biological Phenomena; D061565:Cycloaddition Reaction; D008301:Maleimides / Q000737:chemistry; D015394:Molecular Structure; D009841:Oligonucleotides / Q000737:chemistry*; D011090:Polyenes / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D008301:Maleimides; D009841:Oligonucleotides; D011090:Polyenes; D014867:Water