#$%^&*AU2014208199B220151203.pdf#####ABSTRACT A compound having the formula: R 2 X, NI N TO N N R' H or a salt, tautomer or stereoisomer thereof, wherein: X is halogen, B(OR') 2 or Sn(R*)3; R2 is H, substituted or unsubstituted C1_s alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heterocyclylalkyl, substituted or unsubstituted aralkyl, or substituted or unsubstituted cycloalkylalkyl; R3 is H, or a substituted or unsubstituted C1 _8 alkyl; each R' is independently hydrogen or substituted or unsubstituted C1_3 alkyl, or each R', together with the boron atom and the atoms to which they are attached, form a cyclic boronate; and and R" is a C1_4 alkyl.