SEARCH Articles Figures Tables Annulated Five-Membered Heterocycles with One Heteroatom Five-Membered Aromatic Heterocycles with One Heteroatom Five-membered heterocycles with more than one heteroatom Five-membered heterocycles with one heteroatom Heteroatom heterocycles Heteroatoms Heterocycles Heterocycles with heteroatoms Of heterocycles: five-membered rings with one heteroatom Six-membered heterocycles with more than one heteroatom Six-membered heterocycles with one heteroatom