Reaction Of Osmapentalene Fused(Aza) Osmacyclopropene With Inorganic Nitrogen Oxides

In 2013,our group reported the first CCC pincer compound featured a metal-carbon triple bond within the five-membered ring.We then synthesized a series of metallapentalene derivatives containing a three-membered ring moiety through intrinsic chemistry of cyclic metal carbynes,such as osmapentalene fused osmacyclopropene and osmapentalene fused aza-osmacyclopropene.This dissertation focuses on the reaction of osmapentalene fused(aza)osmacyclopropene with inorganic nitrogen oxides.In chapter 1,the synthetic methods,reactivities,properties,and applications of osmapentalenes,osmapentalynes and aza-osmacyclopropenes are mainly introduced.In addition,the synthesis and reactivities of transition metal-nitroso compounds are introduced,and proposal of the thesis are further discussed.In chapter 2,the ring-opening reaction between osmapentalene fused osmacyclopropene and nitric oxide produced osmapentalene oximes.The reaction of osmapentaiene oximes with one equivalent of nitric acid led to the first CCC pincer compound with dinitroethene functional group.Furthermore,the reaction of osmapentalene oximes with excess nitric acid,nitration reaction of CCC pincer compound occured.In chapter 3,the reactivity of osmapentalene fused aza-osmacyclopropene with nitric oxide or nitroso compounds was investigated.Aza-osmacyclopropene,which stands close to the ester group in the fused-osmapentalene ring,reacted with nitric oxide or nitrosonium tetrafluoroborate,osmacyclopentadienopyridine was acquired through a ring expansion reaction.Aza-osmacyclopropene,which stands close to the triphenylphosphine group in the fused-osmapentalene ring,reacted with nitric oxide,a similar ring expansion reaction occurred,thus,osmacyclopentadienopyridine was isolated.With nitrosonium tetrafluoroborate as a substrate,however,the osmacyclopentadiene derivative was found via a ring opening reaction..In chapter 4,the reactions of the osmapentalenes/osmapentalynes with inorganic nitrogen oxides were investigated.The reaction of osmapentalenes fused osmacyclopropene with silver nitrite led to ligand substitution at osmium center.Simialr reaction occurred when we treated aza-osmapentalenes with nitric oxido.[2+2]cycloaddition reaction of osmapentalynes with sodium nitrite produced osmapentalenes fused osmaoxazete.In addition,the reaction of osmapentalene fused osmaisoxazole with N-bromosuccinimide led to bromination of osmapentalene.In chapter 5,the main points of this dissertation are summarized and next plans are proposed.