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