Heteroatoms and substituent effects: The importance of heteroatom hyperconjugation

A convenient method for synthesis of terpyridinesviaa cooperative vinylogous anomeric based oxidation

“…[33][34][35][36][37][38][39] In the other hand, this concept is a kind of negative hyperconjugation can lead sharing of the electron density from lone-pair orbital to a vacant anti-bonding sigma orbital (n / s*) (Scheme 1). 40,41 Anomeric effect has a potent role to explain some eccentric phenomena in the chemistry knowledge. For instance, anomeric effect justies why bis-peroxides A and B can be more thermodynamically stable than mono-peroxides, and can even melt without decomposition at 131 and 142 C, respectively.…”