Substitution and stereochemical effects in the reactions of combined aminonitrile-oxazolidines with a Grignard reagent

Bail, Marc Le; Pérard, Joëlle; Aitken, David J.; Husson, Henri‐Philippe

doi:10.1016/s0040-4039(99)00980-6

Cited by 4 publications

(3 citation statements)

References 17 publications

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“…Because of the higher yield observed in the series of the 6‘-methoxy-bearing compounds 7 and 10 vs those without this substituent 11 and 12 , we suppose that the additional complexation of one of the magnesium atoms may facilitate the substitution. Such an effect has already been observed for reactions involving Grignard reagents . Moreover, an inspection of the corresponding molecular model does not exclude a similar interaction in our case.…”

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confidence: 53%

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Stereoselective C9 Arylation and Vinylation of Cinchona Alkaloids

2008

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A simple and efficient method for the highly stereoselective C-9 arylation and vinylation of Cinchona alkaloids was developed. Both 9S- and 9R-chloroquinine with PhMgBr yielded 9S-phenylquinine (X-ray structure). The reactions with various aryl and vinyl Grignard reagents resulted in the series of 9S-aryl and vinyl alkaloid derivatives. The stereochemical outcome was rationalized by coordination of the magnesium atom to the quinuclidine nitrogen, thus directing the nucleophilic attack at the C-9 stereogenic center.

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supporting

confidence: 53%

“…Such an effect has already been observed for reactions involving Grignard reagents. 13 Moreover, an inspection of the corresponding molecular model does not exclude a similar interaction in our case.…”

mentioning

confidence: 60%

Stereoselective C9 Arylation and Vinylation of Cinchona Alkaloids

2008

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“…This figure does not take into account potential recycling of materials, notably the minor diastereomer 4b. Since C-2-and C-α-substituted derivatives of compound 2 are accessible, [26] this strategy may turn out to be useful for the preparation of C-2-and/or C-6-substituted derivatives of the title product.…”

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confidence: 99%

Asymmetric Synthesis of (S)‐4‐Oxopipecolic Acid by a 3+3 Atom‐Unit Assembly Strategy

et al. 2002

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Abstract(S)‐4‐Oxopipecolic acid has been prepared in enantiomerically pure form from two readily accessible starting materials, (R)‐N‐(cyanomethyl)‐4‐phenyloxazolidine (2) and 2‐(methoxymethoxy)allyl chloride, (3, MOM‐allyl chloride). This strategy exploits the complementary electrophile/nucleophile reactivity at each end of this pair of 3‐atom unit building blocks. Thus, alkylation of the anion of 2 with 3 (creation of the piperidine C‐2−C‐3 bond) followed by Lewis acid induced cyclisation (creation of the C‐5−C‐6 bond), leads principally to a bicyclic intermediate 5 which incorporates a protected form of the title compound. Subsequent chemical transformations lead to the target molecule in an overall yield of 20% for the five‐step sequence. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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