The present invention relates to novel chemistries which allow for heretofore unobtainable substituted tetracycline compounds which exhibit significant antibacterial activity. The methods disclosed herein utilize reactive tetracycline-based precursor 5 compounds, reactive organic substituent precursors and transition metal catalysts under conditions such that a tetracycline compound substituted with the desired organic substituent is formed. In one embodiment of the invention, a substituted tetracycline compound may be prepared by combining a reactive tetracycline-based precursor compound such as an arene tetracycline diazonium salt, and a reactive organic substituent 10 precursor, eg alkenes, substituted alkenes, vinyl monomers, aromatics and heteroaromatics, in the presence of a transition metal catalyst, such as palladium chloride, under conditions such that a tetracycline compound substituted with the organic substituent is formed. Such compounds may optionally act as intermediates for making other compounds, eg hydrogenation of unsaturated groups on the substituent.
