1- Cyano-2-methyl-2-propene

Intermolecular addition of carbon nucleophiles to the ri2-pyrrolium complexes has shown limited success because of the decreased reactivity of the iminium moiety coupled with the acidity (pKa 18-20) of the ammine ligands on the osmium, the latter of which prohibits the use of robust nucleophiles. Addition of cyanide ion to the l-methyl-2//-pyr-rolium complex 32 occurs to give the 2-cyano-substituted 3-pyrroline complex 75 as one diastereomer (Figure 15). In contrast, the 1-methyl-3//-pyrrolium species 28, which possesses an acidic C-3-proton in an anti orientation, results in a significant (-30%) amount of deprotonation in addition to the 2-pyrroline complex 78 under the same reaction conditions. Uncharacteristically, 78 is isolated as a 3 2 ratio of isomers, presumably via epimerization at C-2.17 Other potential nucleophiles such as the conjugate base of malononitrile, potassium acetoacetate, and the silyl ketene acetal 2-methoxy-l-methyl-2-(trimethylsiloxy)-l-propene either do not react or result in deprotonation under ambient conditions. 

The literature on ammoxidation is very wide. The majority of papers and patents published in this field deal with propene and propane ammoxidation to acrylonitrile, of isobutane and isobutene ammoxidation to methacrylonitrile and methyl-aromatics and methylpyridines (picoUne) ammoxidation to the corresponding cyano-containing compounds, as discussed in the previous sections. A small amount of literature deals with the ammoxidation of the following molecules ... 

Euphococcinine and adaline (333) were synthesized from a 2-cyano-6-oxazolopiperidine [699], An anion at C(2) was condensed with 3-bromo-2-methoxy-l-propene, and after elimination of cyanide, the resultant iminium ion was alkylated with either a methyl- or pentyl-Grignard reagent to form the quaternary carbon. The second ring was closed with an intramolecular Mannich reaction. 

Further substitution possibilities are available from 2-(trimethylsilyl)methyl-2-propenal, prepared in 71 % yield by Swern oxidation of 2-(trimcthylsilyl)methyl-2-propenol23. Reaction with trimethylsilyl cyanide/zinc(II) iodide, aryl- or vinyllithium followed by acetyl chloride, allows access to cyano-, aryl- or vinyl-substituted congeners. 

Cyclopropanecarboxylic acid, 3-[2-chloro-3,3,3-trifiuoro-l-propen-yl]-2,2-dimethyl-, cyano(3-hydroxy-5-phenoxyphenyl)methyl ester... 

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