A compound having structure: or a stereoisomer or pharmaceutically acceptable salt or solvate thereof, wherein: R 1 is: a) hydrogen; b) -P(=O)(OR 3) 2; c) -C(=O)alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; d) -C(=O)heterocyclyl, wherein heterocyclyl is optionally substituted with R 10 and/or R 20; e) -C(=O)carbocyclyl, wherein carbocyclyl is optionally substituted with R 10 and/or R 20; f) -C(=O)N(R 3)alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; g) -C(=O)N(R 3)carbocyclyl, wherein carbocyclyl is optionally substituted with R 10 and/or R 20; h) -C(=O)Oalkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; or i) alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; and wherein: each R 3 is independently hydrogen or alkyl; each R 10 is independently halo, haloalkyl, cyano, nitro, trimethylsilanyl, -OR 30, -SR 30, -OC -R 30, -N(R 30) 2, -C R 30, -C OR 30, -C N(R 30) 2, -N(R 30)C OR 31, -N(R 30)C R 31, -N(R 30)C(=NR 31)N(R 32) 2, -N(R 30)S t R 31 (where t is 1 to 2), -S t OR 30 (where t is 1 to 2), -S p R 30 (where p is 0 to 2) or -S t N(R 30) 2 (where t is 1 to 2), -OP(=O)(OR 30) 2, or when a single atom bears two R 10 groups such two R 10 groups may be taken together to form oxo; each R 20 is independently alkyl, alkenyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclalkyl, heteroaryl or heteroarylalkyl, or when a single atom bears two R 20 groups such two R 20 groups may be taken together to form cycloalkyl, wherein each of said alkyl, alkenyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclalkyl, heteroaryl and heteroarylalkyl groups is optionally substituted with R 10 and/or R 22; each R 22 is alkyl; and each R 30, R 31 and R 32 is independently hydrogen or alkyl. R 1 is: a) hydrogen; b) -P(=O)(OR 3) 2; c) -C(=O)alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; d) -C(=O)heterocyclyl, wherein heterocyclyl is optionally substituted with R 10 and/or R 20; e) -C(=O)carbocyclyl, wherein carbocyclyl is optionally substituted with R 10 and/or R 20; f) -C(=O)N(R 3)alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; g) -C(=O)N(R 3)carbocyclyl, wherein carbocyclyl is optionally substituted with R 10 and/or R 20; h) -C(=O)Oalkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; or i) alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; a) hydrogen; b) -P(=O)(OR 3) 2; c) -C(=O)alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; d) -C(=O)heterocyclyl, wherein heterocyclyl is optionally substituted with R 10 and/or R 20; e) -C(=O)carbocyclyl, wherein carbocyclyl is optionally substituted with R 10 and/or R 20; f) -C(=O)N(R 3)alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; g) -C(=O)N(R 3)carbocyclyl, wherein carbocyclyl is optionally substituted with R 10 and/or R 20; h) -C(=O)Oalkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; or i) alkyl, wherein alkyl is optionally substituted with R 10 and/or R 20; and wherein: each R 3 is independently hydrogen or alkyl; each R 10 is independently halo, haloalkyl, cyano, nitro, trimethylsilanyl, -OR 30, -SR 30, -OC -R 30, -N(R 30) 2, -C R 30, -C OR 30, -C N(R 30) 2, -N(R 30)C OR 31, -N(R 30)C R 31, -N(R 30)C(=NR 31)N(R 32) 2, -N(R 30)S t R 31 (where t is 1 to 2), -S t OR 30 (where t is 1 to 2), -S p R 30 (where p is 0 to 2) or -S t N(R 30) 2 (where t is 1 to 2), -OP(=O)(OR 30) 2, or when a single atom bears two R 10 groups such two R 10 groups may be taken together to form oxo; each R 20 is independently alkyl, alkenyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclalkyl, heteroaryl or heteroarylalkyl, or when a single atom bears two R 20 groups such two R 20 groups may be taken together to form cycloalkyl, wherein each of said alkyl, alkenyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclalkyl, heteroaryl and heteroarylalkyl groups is optionally substituted with R 10 and/or R 22; each R 22 is alkyl; and each R 30, R 31 and R 32 is independently hydrogen or alkyl. each R 3 is independently hydrogen or alkyl; each R 10 is independently halo, haloalkyl, cyano, nitro, trimethylsilanyl, -OR 30, -SR 30, -OC -R 30, -N(R 30) 2, -C R 30, -C OR 30, -C N(R 30) 2, -N(R 30)C OR 31, -N(R 30)C R 31, -N(R 30)C(=NR 31)N(R 32) 2, -N(R 30)S t R 31 (where t is 1 to 2), -S t OR 30 (where t is 1 to 2), -S p R 30 (where p is 0 to 2) or -S t N(R 30) 2 (where t is 1 to 2), -OP(=O)(OR 30) 2, or when a single atom bears two R 10 groups such two R 10 groups may be taken together to form oxo; each R 20 is independently alkyl, alkenyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclalkyl, heteroaryl or heteroarylalkyl, or when a single atom bears two R 20 groups such two R 20 groups may be taken together to form cycloalkyl, wherein each of said alkyl, alkenyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclalkyl, heteroaryl and heteroarylalkyl groups is optionally substituted with R 10 and/or R 22; each R 22 is alkyl; and each R 30, R 31 and R 32 is independently hydrogen or alkyl.