A series of novel phosphonoboronates consisting of PC 1 B, PC n B, PC(X)C n B, and PCC=CB derivatives were evaluated as MMP-2 inhibitors. Structure–activity relationships (SARs) data for the compounds were discovered and are discussed. ... The SAR of a group of novel phosphonoboronate MMP-2 inhibitors is reported. ... The use of both boronates and phosphonates as transition state analogue inhibitors is well known. 6 In addition, boronates were slow to ...