Substituted diphenyloxazoles, the synthesis thereof, and the use thereof as fluorescence probes

1. A method of using a compound of Formula I to monitor an environment, wherein said environment is a cell, said method comprising:

(a) placing said compound in or near said environment;

(b) exposing said compound to a light source, wherein said light source produces light with wavelengths between 200 and 700 nm; and

(c) detecting a fluorescent energy, wherein said fluorescent energy is emitted by said compound; wherein the compound of Formula I is:

wherein

A is a single bond, alkylene, alkenylene, or alkynylene, wherein any of alkylene, alkenylene, and alkynylene is optionally substituted;

R 1 is cycloalkyl, cycloalkenyl, piperazine, pyrrolidine, imidazole, aryl, —OR 3 , —SR 3 , —S(O)R 3 , —S(O) 2 R 3 , —C(O)H, —C(O)OR 3 , —OC(O)R 3 , —C(O)NR 3 R 4 , —NR 3 C(O)R 4 , —OC(O)OR 3 , —OC(O)NR 3 R 4 , NR 3 C(O)OR 4 , —OS(O) 2 OR 3 , —S(O) 2 OR 3 , —S(O)OR 3 , —OP(O)(OR 3 )OR 4 , —P(O)(OR 3 )OR 4 , —P(O)HOR 3 , amidino, guanidino, biguanidino, oxyguanidino, alkyliminoamino, formyliminoamino, or EDTA; and

R 2 is H, alkyl, alkenyl, alkynyl, aryl, arylalkyl, or cycloalkyl, wherein any of alkyl, alkenyl, alkynyl, aryl, arylalkyl, and cycloalkyl is optionally substituted; and

R 3 and R 4 are independently H, alkyl, alkenyl, alkynyl, aryl, or arylalkyl, wherein any of alkyl, alkenyl, alkynyl, aryl, and arylalkyl, is optionally substituted;

or wherein

A is a single bond; and R 1 , R 2 , and A, together with N to which R 1 , R 2 , and A are attached, form a piperazine or thiazolidine, either of which is optionally substituted;

and salts thereof;

with the provisos that, when A is C 1-8 unsubstituted alkyl and R 2 is H or methyl, then R 1 is not —NH 2 , —NHCH 3 , —N(CH 3 ) 2 , or —NHC(O)CH 2 Br;

when A is C 1-3 unsubstituted alkyl and R 2 is H, then R 1 is not —C(O)OH, —C(O)OCH 3 , or —C(O)OCH 2 CH 3 ;

when A is C 1-3 unsubstituted alkyl and R 2 is H, then R 1 is not —NHC(O)C 6 F 5 ;

when A is a single bond and R 2 is H or CH 3 , then R 1 is not phenyl substituted with —B(OH) 2 ; and

when A is a single bond, R 1 , R 2 , and A, together with N to which R 1 , R 2 , and A are attached, do not form unsubstituted morpholinyl.

2. The method of claim 1 , wherein said light source produces light with wavelengths between 300 and 600 nm.

3. The method of claim 2 performed as a fluorescence thermal shift assay.

4. The method of claim 2 , wherein said environment is an endoplasmic reticulum of said cell.

5. The method of claim 2 , wherein said compound is used as a hydroxy reactive probe.

6. The method of claim 2 , wherein said compound is used as a amine reactive probe.

7. The method of claim 2 , wherein said compound is used as a ketone reactive probe.