1 ,3-dipolar cycloadditions 1 1,3-dipolar cycloadditions 1 Azomethine ylides 1 Bisphosphonates 1 Cycloaddition 1 Diels Alder reaction 1 Grigg azomethine ylides 1 Nitrile oxides 1 Nitrogen compounds 1 Nitrogen oxides 1 article 1 azide 1 azides 1 bisphosphonates 1 bisphosphonic acid derivative 1 carbon nuclear magnetic resonance 1 complex formation 1 cycloaddition 1 diethyl 4,4 bis(diethoxyphosphoryl) 5 (4 methoxyphenyl)pyrrolidine 2,2 dicarboxylate 1 diethyl 4,4 bis(diethoxyphosphoryl) 5 pentylpyrrolidine 2,2 dicarboxylate 1 diethyl 4,4 bis(diethoxyphosphoryl) 5 phenylpyrrolidine 2,2 dicarboxylate 1 drug structure 1 ethyl 4,4 bis(diethoxyphosphoryl) 2 nitrobutanoate 1 nitrile oxide 1 nitrile oxides 1 octaethyl (3 nitropentane 1,1,5,5 tetrayl)tetrakis(phosphonate) 1 proton nuclear magnetic resonance 1 tetraethyl vinylidenebisphosphonate 1 tetraethyl(1 benzyl 4,5 dihydro 1h 1,2,3 triazole 4,4 diyl)bisphosphonate 1 tetraethyl(3 methyl 4,5 dihydroisoxazole 5,5 diyl)bisphosphonate 1