Process for the cycloaddition of a (hetero)aryl 1,3-dipole compound with a (hetero)cycloalkyne

A process for preparing a product of a 1,3-dipolar cycloaddition reaction comprising reacting a (hetero)aryl 1,3-dipole compound with a (hetero)cycloalkyne,

• wherein:
• the (hetero)aryl 1,3-dipole compound is defined as a compound comprising a 1,3-dipole functional group, wherein the 1,3-dipole functional group is bonded to a (hetero)aryl group, and wherein the (hetero)aryl 1,3-dipole compound is a (hetero)aryl azide or a (hetero)aryl diazo compound;
• wherein:
• (i) the (hetero)aryl group of the (hetero)aryl 1,3-dipole compound comprises one or more substituents having a positive value for the para-Hammett substituent constant op and/or the meta-Hammett substituent constant om, and/or
• (ii) the (hetero)aryl group of the (hetero)aryl 1,3-dipole compound is an electron-poor (hetero)aryl group, wherein an electron-poor (hetero)aryl group is:
• (ii-a) a (hetero)aryl group wherein the (hetero)aromatic ring system is bearing a positive charge, and/or
• (ii-b) a (hetero)aryl group wherein the ratio {number of π-electrons present in the (hetero)aromatic ring system}:
• {number of protons present in the nuclei of the (hetero)aromatic ring system} is lower than 0.167 for a 6-membered ring, or lower than 0.200 for a 5-membered ring;
• the (hetero)cycloalkyne is an aliphatic (hetero)cycloalkyne, wherein an aliphatic (hetero)cycloalkyne is defined as a (hetero)cycloalkyne wherein both sp1 C-atoms of the (hetero)cycloalkyne carbon-carbon triple bond are bonded to an sp3 C-atom.