Nickel bromide 566 Subject

The first synthesis of polyzonimine (119) was a synthesis of the racemate carried out by Smolanoff and co-workers in 1975 at the time of its isolation and structure elucidation (111). Oxidation of 3,3-dimethylcyclohexene (368) with meto-perchlorobenzoic acid followed by treatment of the epoxide with lithium bromide and HMPA in refluxing benzene gave the carboxal-dehyde 369. The morpholino enamine 370 was then subjected to Michael addition with nitro-ethylene, generated from 2-acetoxy-nitroethane, to afford a nitro aldehyde 37L Ketalization and reduction with Raney nickel then afforded ( )-119 in overall yield for the five steps of 22% (Scheme 45) (111). 

Ketones carrying a sulfone substituent in the -position were subjected to enantioselective hydrogenation of the carbonyl group. With the heterogeneous Raney nickel catalyst, modified with tartaric acid and sodium bromide (see Section 2.3.1.1.), l-methylsulfonyl-2-butanone was reduced to (R)-l-methylsulfonyl-2-butanol, 1-methylsulfonyl-2-heptanone to (R)-l-methylsul-fonyl-2-heptanol, and l-methylsulfonyl-2-deeanone to (/ )-l-methylsulfonyl-2-decanol in 100% yield 67-71% ee51. 

The monoxide of bisdiphenylphosphinomethane forms the salt (117) on being subjected to the Horner reaction with bromobenzene in refluxing benzonitrile in the presence of nickel(n) chloride. Tertiary phosphines react with the u-halogenobenzaldimines (118) (and related u-bromodiarylazo-compounds) under unusually mild conditions (refluxing ethanol) in the presence of nickel(n) bromide as catalyst, with formation of the arylphosphonium salts (119). Only... 

The unsymmetrical acetylene (43) yields cw-(CF3)iN-CH CH-CFs with hydrogen-Raney nickel at 20 C, undergoes slow hydration in the presence of aqueous sulphuric acid and mercuric sulphate at 53 °C to give the propion-amide (CFa)jN CO-CH2 CF3, combines with methanol in the presence of sodium methoxide to yield a 96 4 mixture of (CF3)aN-C(OMe) CH CF3 and (CFj)jN CH C(OMe)-CF3, and when subjected to photochemical hydrobromination gives the 1 1 adduct (CFs)jN-CH CBr-CF3 almost quantitatively. Slow electrophilic hydrobromination of the acetylene can be achieved in the presence of aluminium bromide at 20 °C, the main product being the same as that obtained in the photochemical reaction (H trans to Br in each case) this unexpected direction of addition is suggested to result... 

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