| abstract |
The present invention relates to a process for the coupling of two molecules by means of a Diels-Alder reaction with an inverse electron requirement, which comprises the following steps: reaction of (a) a triazine or tetrazine having one or more electron-pulling substituents on the ring as diene component, with the electron-pulling substituents being selected from among: -COOR, -C(O)NR<SUB>2</SUB>, -CX<SUB>3 </SUB>(X = halogen), -halogen, -CN, -SO<SUB>2</SUB>-R or SO<SUB>3</SUB>-R, -PR<SUB>2</SUB>, where R = H, alkyl, aryl, heterocycle, with these in turn being able, if appropriate, to be substituted by alkyl, -OH, -SH, halogen, aryl, heterocycle, nitro, carboxyamido or amino groups, heterocyclic rings having 1, 2 or 3 N, O or S atoms at a ring size of 5 or 6 ring atoms, with these being substituted by at least one carboxyl, sulfonic acid or phosphonic group, with (b) an isolated double bond or triple bond in a (hetero)carbocyclic ring or an isolated olefinic double bond or triple bond in a linear or branched hydrocarbon chain which may, if appropriate, contain heteroatoms as dienophile component. |