Isoxazoles and their Benzo Derivatives
Isothiazoles and their Benzo Derivatives
Oxazoles and their Benzo Derivatives
Thiazoles and their Benzo Derivatives
Five-membered Selenium-Nitrogen Heterocycles
1,2,3- and 1,2,4- Oxadiazoles
1,2,5-Oxadiazoles and their Benzo Derivatives
1,3,4- Oxadiazoles
1,2,3- Thiadiazoles and their Benzo Derivatives
1,2,4- Thiadiazoles
1,2,5- Thiadiazoles and their Benzo Derivatives
1,3,4- Thiadiazoles
Oxatriazoles and Thiatriazoles
Five-membered Rings Fused with Six-membered Rings
Dioxoles and Oxathioles
1,2-Dithioles
1,3-Dithioles
Five-membered Rings containing Three Oxygen or Sulfur Atoms
Dioxazoles, Oxathiazoles and Dithiazoles
Rings containing One Se or Te Atom and One Other Group VI Atom
Classical Heteropentalenes
Non-classical Heteropentalenes
Two Fused Five-membered Heterocyclic Rings: (iii) 1,6,6aλ4-Trithiapentalenes and Related Systems