Addition of aryllithium compounds to oxime ethers

Oxime ethers as versatile precursors in organic synthesis: a review

“…24,25 Early reports of the successful formation of hydroxylamines 10 from oxime ethers in the presence of organolithium and borontriuoride etherate in THF showed that this method complemented the existing literature in a number of ways. 26 The reaction does not work well with Grignard reagents in THF but toluene was found to be optimal solvent for this reaction. 27,28 The presence of BF 3 $Et 2 O was crucial to do the reaction (Scheme 9).…”

Product Class 5: Hydroxylamines

“…[691] Addition of aryllithium compounds to aldoxime ethers occurs preferentially with the corresponding Z-isomers. [119,692] 3-MeOC 6 H 4 Me 3.0:1 28 [693] Oximes ethers derived from (R)-or (S)-O-(1-phenylbutyl)hydroxylamine add Grignard reagents in the presence of the boron trifluoride-diethyl ether complex to give the appropriate O,N-disubstituted hydroxylamines with high diastereoselectivity. [694] By this route the hydroxylamine 488 is obtained, which subsequently can be converted into (R)-(-)coniine (489) (Scheme 200).…”

Nucleophilic Addition to Imines and Imine Derivatives

“…[119][120][121] Yields in the addition of organometallic reagents to substituted aldoximes are modest and are a function of the isomeric composition of the oxime ethers, as the (Z)-oxime isomers are reported to preferentially react with organolithium reagents (entries 1 and 2, Table 13). 120 The reaction has been employed for the preparation of 6-aminoalkyl-substituted pencillins (entry 3, Table 13). 119 Cyclic oxime ether additions have also been evaluated (entries 4 and 5, Table 13).…”

“…119 Cyclic oxime ether additions have also been evaluated (entries 4 and 5, Table 13). 120,121 With the lability of the nitrogen-oxygen bond, addition to 5-substituted isoxazolines provides a potential avenue for stereospecific synthesis of substituted 3-aminoalcohols (entry 5, Table 13). The reaction of ketoximes with Grignard reagents has been extensively investigated and provides aziridines in low/moderate yields.…”