The insertion of methanesulfonylnitrene into C–H and O–H bonds was investigated by the photolysis of methanesulfonyl azide In hydrocarbons and in alcohols. The relative reactivity of the sulfonylnitrene toward C–H bonds of hydrocarbons was found to be smaller than that of ethoxycarbonylnitrene, whereas the reactivity of the sulfonylnitrene toward O–H bonds of alcohols was larger than that of the carbonylnitrene.
The proton acid-catalyzed decomposition of 3-aryl-2-diazo-3-hydroxy-1-phenylpropanone (1) gave aryl and hydrogen migration products. The former was the enol-form (2) of 2-aryl-3-phenyl-1,3-propanedione and the latter was the enol- (3) and keto-form (4) of 1-aryl-3-phenyl-1,3-propanedione. The product ratios, 2/(3+4), were affected by the catalysts and solvents used. More polar solvents favored the formation of aryl migration products (2). On the other hand, the BF3-catalyzed decomposition of 1 gave acetylenic ketones as main products along with 2, 3, and 4. The TsOH-catalyzed decomposition of 2-diazo-3-hydroxy-3-phenyl-1-indanone, (cyclic α-diazo β-hydroxy ketone), gave 2-phenyl-1,3-indandione quantitatively through phenyl migration.
The copper chelate-catalyzed decomposition of o-methoxycarbonyl-α-diazoacetophenone was carried out in benzene. The reaction gave a dimer of a carbonyl ylide intermediate. The intermediate was trapped with dipolarophiles such as trans-dibenzoylethylene, ethyl fumarate, isoprene and dimethyl acetylenedicarboxylate, yielding 1,3-dipolar adducts in a stereospecific and stereoselective manner. Similar results were obtained in the catalytic decomposition of o-(n-butoxycarbonyl)-α-diazoacetophenone. The configuration of adducts and the mechanism of the reaction are discussed.
Ethyl azidoformate was photolyzed in three to six membered cyclic ethers. The α-C–H and α-methyl C–H bonds of cyclic ethers were observed to have unusually large reactivities compared with those of the corresponding C–H bonds of hydrocarbons in the insertion of ethoxycarbonylnitrene. On the anomalous reactivities, a mechanism has been advanced in which an O–N ylide is included as an intermediate of the insertion reaction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.