Fused cyclooctyne compounds and their use in metal-free click reactions

A compound of the Formula (IIa):

• wherein:
• n is 0 to 8;
• p is 0 or 1;
• R3 is selected from the group consisting of [(L)p-Q], hydrogen, halogen, C1-C24 alkyl groups, C6-C24 (hetero)aryl groups, C7-C24 alkyl(hetero)aryl groups and C7-C24 (hetero)arylalkyl groups, the alkyl groups optionally being interrupted by one of more hetero-atoms selected from the group consisting of O, N and S, wherein the alkyl groups, (hetero)aryl groups, alkyl(hetero)aryl groups and (hetero)arylalkyl groups are independently optionally substituted with one or more substituents independently selected from the group consisting of C1-C12 alkyl groups, C2-C12 alkenyl groups, C2-C12 alkynyl groups, C3-C12 cycloalkyl groups, C1-C12 alkoxy groups, C2-C12 alkenyloxy groups, C2-C12 alkynyloxy groups, C3-C12 cycloalkyloxy groups, halogens, amino groups, oxo groups and silyl groups, wherein the alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, alkoxy groups, alkenyloxy groups, alkynyloxy groups and cycloalkyloxy groups are optionally substituted, the alkyl groups, the alkoxy groups, the cycloalkyl groups and the cycloalkoxy groups being optionally interrupted by one of more hetero-atoms selected from the group consisting of O, N and S, wherein the silyl groups are represented by the formula (R4)3Si—, wherein R4 is independently selected from the group consisting of C1-C12 alkyl groups, C2-C12 alkenyl groups, C2-C12 alkynyl groups, C3-C12 cycloalkyl groups, C1-C12 alkoxy groups, C2-C12 alkenyloxy groups, C2-C12 alkynyloxy groups and C3-C12 cycloalkyloxy groups, wherein the alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, alkoxy groups, alkenyloxy groups, alkynyloxy groups and cycloalkyloxy groups are optionally substituted, the alkyl groups, the alkoxy groups, the cycloalkyl groups and the cycloalkoxy groups being optionally interrupted by one of more hetero-atoms selected from the group consisting of O, N and S;
• L is a linking group selected from linear or branched C1-C24 alkylene groups, C2-C24 alkenylene groups, C2-C24 alkynylene groups, C3-C24 cycloalkylene groups, C5-C24 cycloalkenylene groups, C8-C24 cycloalkynylene groups, C7-C24 alkyl(hetero)arylene groups, C7-C24 (hetero)arylalkylene groups, C8-C24 (hetero)arylalkenylene groups, C9-C24 (hetero)arylalkynylene groups, the alkylene groups, alkenylene groups, alkynylene groups, cycloalkylene groups, cycloalkenylene groups, cycloalkynylene groups, alkyl(hetero)arylene groups, (hetero)arylalkylene groups, (hetero)arylalkenylene groups and (hetero)arylalkynylene groups optionally being substituted with one or more substituents independently selected from the group consisting of C1-C12 alkyl groups, C2-C12 alkenyl groups, C2-C12 alkynyl groups, C3-C12 cycloalkyl groups, C5-C12 cycloalkenyl groups, C8-C12 cycloalkynyl groups, C1-C12 alkoxy groups, C2-C12 alkenyloxy groups, C2-C12 alkynyloxy groups, C3-C12 cycloalkyloxy groups, halogens, amino groups, oxo and silyl groups, wherein the silyl groups can be represented by the formula (R4)3Si—, wherein R4 is defined as above;
• Q is a functional group selected from the group consisting of hydrogen, halogen, R6, —CH═C(R6)2, —C≡CR6, —[C(R6)2C(R6)2O]q—R6, wherein q is in the range of 1 to 200, —CN, —N3, —NCX, —XCN, —XR6, —N(R6)2, —+N(R6)3, —C(X)N(R6)2, —C(R6)2XR6, —C(X)R6, —C(X)XR6, —S(O)R6, —S(O)2R6, —S(O)OR6, —S(O)2OR6, —S(O)N(R6)2, —S(O)2N(R6)2, —OS(O)R6, —OS(O)2R6, —OS(O)OR6, —OS(O)2OR6, —P(O)(R6)(OR6), —P(O)(OR6)2, —OP(O)(OR6)2, —Si(R6)3, —XC(X)R6, —XC(X)XR6, —XC(X)N(R6)2, —N(R6)C(X)R6, —N(R6)C(X)XR6 and —N(R6)C(X)N(R6)2, wherein X is oxygen or sulphur and wherein R6 is independently selected from the group consisting of hydrogen, halogen, C1-C24 alkyl groups, C6-C24 (hetero)aryl groups, C7-C24 alkyl(hetero)aryl groups and C7-C24 (hetero)arylalkyl groups;
• R1 is independently selected from the group consisting of hydrogen, C1-C24 alkyl groups, C6-C24 (hetero)aryl groups, C7-C24 alkyl(hetero)aryl groups and C7-C24 (hetero)arylalkyl groups;
• and
• R2 is independently selected from the group consisting of halogen, —OR6, —NO2, —CN, —S(O)2R6, C1-C12 alkyl groups, C1-C12 aryl groups, C1-C12 alkylaryl groups and C1-C12 arylalkyl groups, wherein R6 is as defined above, and wherein the alkyl groups, aryl groups, alkylaryl groups and arylalkyl groups are optionally substituted.