Caging-group-free photoactivatable fluorescent dyes and their use

A compound, in particular a photoactivatable fluorescent dye, having the structural formula I:

• wherein:
• R1, R2, R3, R4, R5, R6, R7 and R8, independently of each other are selected from H, halogen, SO3H, CO2H, CN, NO2, CO2R, SO2R— with R in CO2R or SO2R being selected from C1 to C4 unsubstituted alkyl , and an unsubstituted or substituted moiety, in particular an unsubstituted or halogen-, amino-, hydroxyl-, SO3H— and/or carboxyl-substituted moiety, which is selected from C1-C20 alkyl, C3-C8 cycloalkyl, C1-C20 alkoxy, C2-C20 alkylene, C2-C20 alkylyne, C7-C20 alkylaryl, phenyl and 5- or 6-membered ring heteroaryl, or a combination thereof;
• and where the substituents R6 and R7, taken together with the atoms to which they are bound, may form a 5-8 membered ring structure;
• and/or where the substituents R7 and R8, taken together with the atoms to which they are bound, may form a 5-8 membered ring structure;
• R9, R10, R11, R12 are:
• a. independently selected from H, unsubstituted and substituted C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 acyl, C1-C8 alkoxycarbonyl, and C7-C12 alkylaryl, and unsubstituted phenyl or phenyl substituted by unsubstituted alkyl, halogen, alkoxy, NO2, CO2H, CO2R and/or CONR2— with each R in CO2R or CONR2 being selected independently from C1 to C4 unsubstituted alkyl-;
• or
• b. R9 together with R10 and a nitrogen atom to which they are bound, and/or R11 together with R12 and a nitrogen atom to which they are bound form a 3-7 membered ring structure;
• or
• c. R9 and/or R11 are independently selected from H and unsubstituted and substituted C1-C8 alkyl, C3-C8 cycloalkyl, and C7-C12 alkylaryl;
• and R10 together with R2 or R3 and the atoms to which they are bound form a 5-7 membered ring structure, and/or R12 together with R4 or R5 and the atoms to which they are bound form a 5-7 membered ring structure;
• d. R9 together with R2 and the atoms to which they are bound form a 5-7 membered ring structure, and/or R10 together with R3 and the atoms to which they are bound form a 5-7 membered ring structure, and/or R11 together with R4 and the atoms to which they are bound form a 5-7 membered ring structure, and/or R12 together with R5 and the atoms to which they are bound form a 5-7 membered ring structure;
• X is independently selected from:
• a. O or S atom or SO2 group;
• b. NR13 or P(═O)R13 group, where R13 is selected from H, unsubstituted and substituted C1-C12 alkyl, C3-C8 cycloalkyl, C1-C20 alkoxy, C1-C20 alkoxycarbonyl, C2-C20 acyl, C2-C20 alkylsulfonyl, C2-C20 alkylene, C2-C20 alkylyne and C7-C20 alkylaryl, phenyl and 5- or 6-membered ring heteroaryl, or a combination thereof;
• c. SiR14R15 or GeR14R15 group, where R14 and R15 are each independently selected from unsubstituted and substituted C1-C12 alkyl, C3-C8 cycloalkyl, C1-C20 alkoxy, C2-C20 alkylene, C2-C20 alkylyne and C7-C20 alkylaryl, phenyl and 5- or 6-membered ring heteroaryl, or a combination thereof,
• or where both substituents R14 and R15, taken together with the Si or Ge to which they are attached, form a 4-7 membered ring structure;
• d. CR16R17 group, where R16 and R17 are each independently selected from H, F, CF3, CN, COR18, CO2R18, SO2R18, CONR18R19—where R18 and R19 in COR18, CO2R18, SO2R18, and CONR18R19 are each independently selected from unsubstituted and substituted C1-C12 alkyl, C3-C8 cycloalkyl, C1-C20 alkoxy, C2-C20 alkylene, C2-C20 alkylyne and C7-C20 alkylaryl, phenyl and 5- or 6-membered ring heteroaryl, or a combination thereof, unsubstituted and substituted C1-C12 alkyl, C3-C8 cycloalkyl, C1-C20 alkoxy, C2-C20 alkylene, C2-C20 alkylyne and C7-C20 alkylaryl, phenyl and 5- or 6-membered ring heteroaryl, or a combination thereof,
• or where both substituents R16 and R17, taken together with the C atom to which they are attached, form a 4-7 membered ring structure;
• Y is independently selected from:
• a. O or S atom;
• b. NR20 group, where R20 is selected from H, unsubstituted and substituted C1-C12 alkyl, C3-C8 cycloalkyl, C1-C20 alkoxy, C2-C20 acyl, C2-C20 alkylsulfonyl, C2-C20 alkylene, C2-C20 alkylyne and C7-C20 alkylaryl, phenyl and 5- or 6-membered ring heteroaryl, or a combination thereof;
• c. CR21R22 group, where R21 and R22 are each independently selected from H, F, CF3, CN, COR23, CO2R23, SO2R23, CONR23R24—where R23 and R24 in COR23, CO2R23, SO2R23, CONR23R24 are each independently selected from unsubstituted and substituted C1-C12 alkyl, C3-C8 cycloalkyl, C1-C20 alkoxy, C2-C20 alkylene, C2-C20 alkylyne and C7-C20 alkylaryl, phenyl and 5- or 6-membered ring heteroaryl, or a combination thereof, unsubstituted and substituted C1-C12 alkyl, C3-C8 cycloalkyl, C1-C20 alkoxy, C2-C20 alkylene, C2-C20 alkylyne and C7-C20 alkylaryl, unsubstituted and substituted phenyl, unsubstituted and substituted 5- or 6-membered ring heteroaryl, or a combination thereof,
• or where both substituents R21 and R22, taken together, form a 4-7 membered ring structure.