Fluorous capping reagents and methods for peptide purification

A method of preparing a fluorocarbon compound, comprising the step of:

• treating a compound comprising a nucleophilic functional group with a trivalent iodonium compound to generate a fluorocarbon compound, wherein said trivalent iodonium compound is represented by formula I:
• wherein
• R1 represented by formula
• wherein R8 is H, alkyl, or fluoroalkyl;
• R9 is H, F, alkyl, or fluoroalkyl;
• R10 is H or F;
• X is O, NR5, or S;
• m is 1-18 inclusive;
• p is 0-10 inclusive;
• q is 1-10 inclusive;
• r is 1, 2, 3, 4, 5, 6, 7, or 8;
• s is 1, 2, 3, 4, 5, or 6;
• and t is 0, 1, 2, 3, 4, 5, or 6;
• R2 is aryl, heteroaryl, alkenyl, or alkynyl;
• R3 and R4 represent independently for each occurrence —SO2R5, —C(O)R5, —CO2R5, —C(O)N(R6)2, —C(S)R5, —C(S)OR5, —C(S)N(R6)2, or -aryl-(R7)n;
• R5 represents independently for each occurrence alkyl, fluoroalkyl, chloroalkyl, aryl, or aralkyl;
• R6 represents independently for each occurrence H, alkyl, fluoroalkyl, chloroalkyl, aryl, or aralkyl;
• R7 represents independently for each occurrence nitro, cyano, halogen, —SO2R5, —C(O)R5, —CO2R5, or —C(O)N(R6)2;
• and
• n is independently 0, 1, 2, 3, 4, or 5 in accord with the rules of valence.

A compound represented by formula I:

• wherein
• R1 is fluoroheteroalkyl, fluorocycloalkyl, fluoroheterocycloalkyl, fluorocycloalkyl(C1-C6)alkyl, fluoroheterocycloalkyl(C1-C6)alkyl, (fluoroalkyl)aralkyl, fluoroaralkyl, or fluoroalkenyl(C1-C6)alkyl;
• R2 is aryl, heteroaryl, alkenyl, or alkynyl;
• R3 and R4 represent independently for each occurrence —SO2R5, —C(O)R5, —CO2R5, —C(O)N(R6)2, —C(S)R5, —C(S)OR5, —C(S)N(R6)2, or -aryl-(R7)n;
• R5 represents independently for each occurrence alkyl, fluoroalkyl, chloroalkyl, alkenyl, aryl, or aralkyl;
• R6 represents independently for each occurrence H, alkyl, fluoroalkyl, chloroalkyl, aryl, or aralkyl;
• R7 represents independently for each occurrence nitro, cyano, halogen, —SO2R5, —C(O)R5, —CO2R5, or —C(O)N(R6)2;
• and
• n is independently 0, 1, 2, 3, 4, or 5 in accord with the rules of valence.

A method of preparing a fluorocarbon compound, comprising the step of:

• treating a compound comprising a nucleophilic functional group with a trivalent iodonium compound to generate a fluorocarbon compound, wherein said trivalent iodonium compound is represented by formula I:
• wherein
• R1 is fluoroheteroalkyl, fluorocycloalkyl, fluoroheterocycloalkyl, fluorocycloalkyl(C1-C6)alkyl, fluoroheterocycloalkyl(C1-C6)alkyl, (fluoroalkyl)aralkyl, fluoroaralkyl, or fluoroalkenyl(C1-C6)alkyl;
• R2 is aryl, heteroaryl, alkenyl, or alkynyl;
• R3 and R4 represent independently for each occurrence —SO2R5, —C(O)R5, —CO2R5, —C(O)N(R6)2, —C(S)R5, —C(S)OR5, —C(S)N(R6)2, or -aryl-(R7)n;
• R5 represents independently for each occurrence alkyl, fluoroalkyl, chloroalkyl, aryl, or aralkyl;
• R6 represents independently for each occurrence H, alkyl, fluoroalkyl, chloroalkyl, aryl, or aralkyl;
• R7 represents independently for each occurrence nitro, cyano, halogen, —SO2R5, —C(O)R5, —CO2R5, or —C(O)N(R6)2;
• and
• n is independently 0, 1, 2, 3, 4, or 5 in accord with the rules of valence.