Generation and Rearrangements of Ylides from Tertiary Amines and α‐Diazo Ketones − Very High Catalytic Activity of [RuCl(η5‐C5H5)(PPh3)2]
The reaction of N,N-dimethyl-2-propen-1-amine, N,N-dimethylbenzylamine and N,N-dimethyl-2-propyn-1-amine with the α-diazo ketones N2CHCOR [R = Me (2a), Et (2b), nPr (2c), iPr (2d), (CH2)10Me (2e), (CH2)14Me (2f) or Ph (2g)] in a 1:1 molar ratio, catalysed by the complex [RuCl(η5-C5H5)(PPh3)2] (1) (1% mol), have been investigated. Noticeably, the corresponding α-amino ketones 3a−g, 4a−g and 5a−g are readily and quantitatively formed by rearrangement of transient nitrogen ylides. Compounds 3−5, most of which have not yet been reported, have been isolated and fully characterised by IR, 1H and 13C NMR spectroscopy and GC-MS. It has been proved that complex 1 is an excellent and specific catalyst for the generation of nitrogen ylides from diazo carbonyls.