The molecules of this week are definitely recognized as morpholines! Not just morpholine derivatives, but rather constrained analogues with a geometric construction in the cycle. Why did we select them as "molecules of the week"? It is simple: morpholine is one of the most popular fragments in medicinal chemistry and is among TOP 30 most frequently used ring systems for small molecule drugs.[1] Morpholine has outstanding solubility and stability and these constrained analogues would definitely tune up activity and properties of your molecules!
![Chemical structure of tert-butyl 1-(aminomethyl)-2-oxa-5-azabicyclo[2.2.1]heptane-5-carboxylate - CSSB00010366113](/st/structure/200/021f6c39362ff56497a150c56b8b3b96/CC%2528C%2529%2528C%2529OC%2528%253DO%2529N1CC2%2528CN%2529CC1CO2.png)
![Chemical structure of 6-oxa-3-azabicyclo[3.2.1]octane - CSMB00000758631](/st/structure/200/0af9fe88124b31dc6231656034a52fc2/C1OC2CC1CNC2.png)
![Chemical structure of 2-oxa-5-azabicyclo[2.2.1]heptan-3-one - CSMB00010438920](/st/structure/200/fda346c3731a0af385332ba66b8637a4/O%253DC1OC2CNC1C2.png)
![Chemical structure of 5-[(tert-butoxy)carbonyl]-2-oxa-5-azabicyclo[2.2.1]heptane-4-carboxylic acid - CSSB00015727668](/st/structure/200/0c6c673d94e0a8ecef6397c8f8e54ba9/CC%2528C%2529%2528C%2529OC%2528%253DO%2529N1CC2CC1%2528CO2%2529C%2528O%2529%253DO.png)
![Chemical structure of tert-butyl 1-(iodomethyl)-2-oxa-5-azabicyclo[2.2.1]heptane-5-carboxylate - CSSB00025796201](/st/structure/200/a88aab418dc43f52e53db2c299d3d3f2/CC%2528C%2529%2528C%2529OC%2528%253DO%2529N1CC2%2528CI%2529CC1CO2.png)
[1] R. D. Taylor, M. Maccoss, A. D. G. Lawson, J. Med. Chem. 2014, 57, 5845–5859.