Methods and reagents for radiolabeling

A method comprising the steps of:

• a) providing a trialkyltin compound of formula I:
• wherein:
• X is —CH2—, —O—, or —S—;
• Y1 and Y2 are independently —CR3a— or —N—;
• Z1 Z2, and Z3 are independently —CH— or —N—;
• R1 is hydrogen or halogen;
• L is a straight or branched, C2-14 aliphatic group wherein one or more carbons are optionally and independently replaced by —Cy—, —NR—, —N(R)C(O)—, —C(O)N(R)—, —C(O)N(O)—, —N(R)SO2—, —SO2N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —S—, —SO—, or —SO2—,
• each -Cy- is independently an optionally substituted 3-8 membered bivalent, saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an optionally substituted 8-10 membered bivalent saturated, partially unsaturated, or aryl bicyclic ring having 0-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• R2 is hydrogen or an optionally substituted group selected from the group consisting of C1-6 aliphatic, phenyl, 3- to 7-membered saturated or partially unsaturated monocyclic carbocyclyl, 3- to 7-membered saturated or partially unsaturated monocyclic heterocyclyl having 1-2 heteroatoms selected from oxygen, nitrogen, or sulfur, 5- to 6-membered heteroaryl having 1-4 heteroatoms selected from oxygen, nitrogen, or sulfur, 7- to 10-membered saturated or partially unsaturated bicyclic carbocyclyl, 7- to 10-membered saturated or partially unsaturated bicyclic heterocyclyl having 1-4 heteroatoms selected from oxygen, nitrogen, or sulfur, 7- to 10-membered bicyclic heteroaryl having 1-4heteroatoms selected from oxygen, nitrogen, or sulfur, or 8- to 10-membered bicyclic aryl;
• wherein —L—R2 does not contain a Boc-protected secondary amine;
• each R3 is independently halogen, —NO2, —CN, —OR, —SR, —N(R)2, —C(O)R, —CO2R, —C(O)C(O)R, —C(O)CH2C(O)R, —S(O)R, —S(O)2R, —C(O)N(R)2, —SO2N(R)2, —OC(O)R, —N(R)C(O)R, —N(R)N(R)2, or optionally substituted C1-6 aliphatic or pyrrolyl;
• or
• two R3 groups are taken together with their intervening atoms to form Ring A, wherein Ring A is a 3- to 7-membered partially unsaturated carbocyclyl, phenyl, a 5- to 6-membered partially unsaturated monocyclic heterocyclyl having 1-2 heteroatoms selected from oxygen, nitrogen, or sulfur, 5- to 6-membered heteroaryl having 1-4heteroatoms selected from oxygen, nitrogen, or sulfur, or 6-membered aryl;
• R3a is R3 or hydrogen;
• R4 is C1-4alkyl;
• each R is independently hydrogen or an optionally substituted group selected from C1-6 aliphatic, phenyl, 3- to 7-membered saturated or partially unsaturated carbocyclyl, 3- to 7- membered saturated or partially unsaturated monocyclic heterocyclyl having 1-2heteroatoms selected from oxygen, nitrogen, or sulfur, or 5- to 6-membered heteroaryl having 1-4 heteroatoms selected from oxygen, nitrogen, or sulfur, or:
• two R groups on the same nitrogen are taken together with their intervening atoms to form an optionally substituted ring selected from 3- to 7-membered saturated or partially unsaturated monocyclic heterocyclyl having 1-2 heteroatoms selected from oxygen, nitrogen, or sulfur, or 5- to 6-membered heteroaryl having 1-4 heteroatoms selected from oxygen, nitrogen, or sulfur;
• and
• b) reacting the trialkyltin compound of formula I under suitable conditions to provide a compound of formula IL:
• wherein RL is a radiolabel.