Preferred template and scaffold structures also include those that are capable of reacting with reagents without {HEAD ~ the need} for {TAIL ~ a catalyst} 
for
Preferred template and scaffold structures also include those that are capable of reacting with reagents without { HEAD ~ the need } for { TAIL ~ a catalyst }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL