Peri-Annulated Heterocyclic Systems. Part I

The chapter presents various aspects of the chemistry of peri-fused heterocyclic systems taking into account the new findings. The chapter discusses the previously developed sequence, describing successively the compounds with larger heterocycles, with increasing number of heteroatoms in the heteroatom order N,O,S, and occasionally other heteroatoms. This chapter draws attention to the peri-fused heterocyclic naphthalene derivatives with a four-membered heterocyclic ring. Those peri-annulated heterocycles with a closed π-system that possess a double bond or another π- or p-electron “bridge” situated in the peri-position of the naphthalene ring opposite to the heterocycle should be set apart. A large number of stable representatives of four-membered heterocycles with nitrogen or oxygen ring heteroatom are described, among them also their benzoannulated derivatives. The chapter describes the peri-annulated heterocyclic naphthalene derivatives with a four-membered hetero ring— namely, (1)Naphth[1,8-bc]azete, (2)Naphtho[1,8-bc]phosphate, (3)Naphth[1,8-bc]oxete, (4)Naphtho[1,8-bc]thiete and its S-Oxides (5)Naphtho[1,8-bc]borete and (6)Naphtho[1,8-bc]silete .