Diazo compounds nickel carbonyl

Nickel peroxide, an undefined black oxide of nickel, is prepared from nickel sulfate hexahydrate by oxidation in alkaline medium with an ozone-oxygen mixture [929] or with sodium hypochlorite [930, 931, 932, 933]. Its main applications are the oxidation of aromatic side chains to carboxyls [933], of allylic and benzylic alcohols to aldehydes in organic solvents [929, 932] or to acids in aqueous alkaline solutions [929, 930, 932], and of aldehydes to acids [934, the conversion of aldehyde or ketone hydrazones into diazo compounds [935] the dehydrogenative coupling of ketones in the a positions with respect to carbonyl groups [931] and the dehydrogenation of primary amines to nitriles or azo compounds [936]. 

Treatment of diazo compounds with an excess of nickel carbonyl in ethanol leads to the formation of carboxylic esters (64). 

Reactions of diazo compounds with nickel carbonyl s. 16, 847 Nickel sulfatejpotassium cyanide o-Hydroxynitriles from diazo oxides... 

Transmetallation of 1-6 or treatment of 1-6 with Lewis acid further broadens the scope of its reaction chemistry. In the presence of CuCl, the reaction of 1-6 with diazo dicarboxylate affords pyridazine derivatives [27]. In the presence of CuCl or nickel complexes, the reaction of 1-6 with alkynes leads to benzene derivatives [28, 29]. Transmetallation of 1-6 with Bids allows further reaction with 2-oxo malonate to give 2/7-pyran derivatives [27]. Transmetallation of 1-6 with CrCls followed by reaction with isocyanates affords pyridine derivatives [30]. Transmetallation of 1-6 with AICI3 followed by reaction with aldehydes affords pentasubstimted cyclo-pentadiene derivatives [31]. Under the similar condition, 1-6 reacts with nitroso compounds to form pyrrole derivatives [32]. Addition of n-butyl lithium activates 1-6 and allows further reaction with carbon monoxide, which leads to carbonylation and affords 2-cyclopentenone upon hydrolysis [33]. 

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