Journal of Organic Chemistry 2004-04-30

Reactivity and enantioselectivity in the reactions of scalemic stereogenic alpha-(N-carbamoyl)alkylcuprates.

R Karl Dieter, Gabriel Oba, Kishan R Chandupatla, Chris M Topping, Kai Lu, Rhett T Watson

Index: J. Org. Chem. 69(9) , 3076-86, (2004)

Full Text: HTML

Abstract

Stereogenic 2-(N-carbamoyl)pyrrolidinylcuprates prepared from scalemic (i.e., enantioenriched) N-Boc-2-lithiopyrrolidine and THF soluble CuCN.2LiCl react with vinyl iodides, vinyl triflates, beta-iodo-alpha,beta-enoates, propargyl mesylates, and allyl bromide to afford the substitution products with excellent enantioselectivity. Excellent enantiomeric ratios are obtained in the conjugate addition reactions with methyl vinyl ketone while low enantiomeric ratios can be achieved with acrylate esters using HMPA/TMSCl activation. Enantiomeric ratios vary with substrate substitution patterns and the observed enantioselectivities appear to be more a function of cuprate-electrophile reactivities than of the reaction type (e.g., substitution, conjugate addition). Low enantiomeric ratios are obtained with the alpha-(N-carbamoyl)benzylcuprates. The lithium-copper transmetalation and cuprate vinylation reactions proceed with retention of configuration.

Related Compounds

  • allyl bromide
  • Dimethylolurea

Related Articles:

Novel amphiphilic cationic porphyrin and its Ag(II) complex as potential anticancer agents.

2014-11-01

[J. Inorg. Biochem. 140 , 94-103, (2014)]

Molecular self assembly of mixed comb-like dextran surfactant polymers for SPR virus detection.

2014-11-04

[Carbohydr. Polym. 112 , 440-7, (2014)]

S-allylcysteine prevents cisplatin-induced nephrotoxicity and oxidative stress.

2014-09-01

[J. Pharm. Pharmacol. 66(9) , 1271-81, (2014)]

Bioconversion of ethyl 4-chloro-3-oxobutanoate by permeabilized fresh brewer's yeast cells in the presence of allyl bromide.

2007-02-01

[J. Ind. Microbiol. Biotechnol. 34(2) , 151-6, (2007)]

Design and synthesis of modular oxazoline ligands for the enantioselective chromium-catalyzed addition of allyl bromide to ketones.

2007-03-14

[J. Am. Chem. Soc. 129(10) , 2752-3, (2007)]

More Articles...