Protective groups and methods for protecting benzoxaboroles or oxaboroles
The present invention relates in part to protective groups that can be used to reversibly protect benzoxaboroles and/or oxaboroles and yield the corresponding protected complexes. The invention further relates to the use of these protective groups to protect benzoxaboroles and/or oxaboroles.
1. A method of protecting a boronic acid group, the method comprising reacting a boronic acid containing compound with a compound of formula (III) or formula (IV):
wherein:
each occurrence of R 2 is independently selected from the group consisting of H, optionally substituted C 1 -C 6 alkyl, halogen, optionally substituted C 2 -C 6 alkenyl, optionally substituted C 2 -C 6 alkynyl, optionally substituted C 3 -C 8 cycloalkyl, optionally substituted C 1 -C 8 heteroalkyl, optionally substituted C 3 -C 8 heterocycloalkyl, and optionally substituted C 1 -C 6 perhaloalkyl;
each occurrence of R 4 is independently selected from the group consisting of H, optionally substituted C 1 -C 6 alkyl, optionally substituted C 3 -C 8 cycloalkyl, optionally substituted C 1 -C 8 heteroalkyl, and optionally substituted C 3 -C 8 heterocycloalkyl; and
each occurrence of R 5 is independently selected from the group consisting of H, halogen nitro, nitrile, and optionally substituted C 1 -C 6 alkyl.
2. The method of claim 1 , wherein the boronic acid containing compound is a (benz)oxaborole or oxaborole.
3. The method of claim 2 , wherein the (benz)oxaborole or oxaborole is a compound of formula:
wherein:
each occurrence of R 1 is independently selected from the group consisting of H, OH, halogen, amine, carboxylic acid, C(═O)O(C 1 -C 4 )alkyl, C(═O)NH 2 , C(═O)NH(C 1 -C 4 )alkyl, C(═O)N((C 1 -C 4 )alkyl) 2 , C(═NH)NH 2 , phosphoric acid, phosphonate, sulfonamide, nitro, cyano, optionally substituted C 1 -C 6 alkyl, optionally substituted C 2 -C 6 alkenyl, optionally substituted C 2 -C 6 alkynyl, optionally substituted C 3 -C 8 cycloalkyl, optionally substituted C 1 -C 8 heteroalkyl, optionally substituted C 3 -C 8 heterocycloalkyl, optionally substituted C 1 -C 6 perhaloalkyl, optionally substituted C 1 -C 6 alkoxy, optionally substituted aryl, optionally substituted aryloxy, optionally substituted heteroaryl, optionally substituted heteroaryloxy, and optionally substituted benzyl; and
each occurrence of R 3 is independently selected from the group consisting of H, OH, halogen, amine, optionally substituted C 1 -C 6 alkyl, optionally substituted C 2 -C 6 alkenyl, optionally substituted C 2 -C 6 alkynyl, optionally substituted C 3 -C 8 cycloalkyl, optionally substituted C 1 -C 8 heteroalkyl, optionally substituted C 3 -C 8 heterocycloalkyl, optionally substituted C 1 -C 6 perhaloalkyl, optionally substituted C 1 -C 6 alkoxy, optionally substituted aryl, optionally substituted aryloxy, optionally substituted heteroaryl, optionally substituted heteroaryloxy, optionally substituted benzyl, carboxylic acid, C(═O)O(C 1 -C 4 )alkyl, C(═O)NH 2 , C(═O)NH(C 1 -C 4 )alkyl, C(═O)N((C 1 -C 4 )alkyl) 2 , SO 2 NH 2 , and C(═NH)NH 2 .
4. The method of claim 1 , wherein the boronic acid containing compound is selected from the group consisting of:
5. The method of claim 1 , comprising reacting the boronic acid containing compound with a compound of formula (IIIa) or formula (IVa):