Conjugate addition reactions of alpha-aminoalkylcuprates with alpha, beta-alkenyl-, alpha,beta-alkynyl-, alpha,beta-beta,gamma-allenyl-, and alpha,beta-gamma,delta-dienyl carboxylic acid derivatives, nitriles, and sulfoxides.
alpha-Aminoalkylcuprates prepared from alpha-lithio carbamates and CuCN.2LiCl participate in 1,4-addition reactions with alpha, beta-unsaturated esters, thiol esters, imides, and nitriles in poor to excellent yields depending upon the electron-withdrawing substituent and the substitution pattern of the unsaturated substrate. These reagents also undergo conjugate addition reactions with alpha,beta-alkynyl esters, sulfoxides, and nitriles and with alpha,beta-beta,gamma-unsaturated allenyl esters. Excellent stereocontrol is achieved in the conjugate additions of alpha-aminoalkylcuprates to the allenyl esters, while poor stereoselectivity results in the conjugate additions to the alkynyl derivatives. Deprotection and cyclization of the alkynyl adducts affords pyrrolin-2-ones, while similar treatment of the allenyl adducts affords 4-alkylidine- pyrrolidin-2-ones and pyrrolizidinones.
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Hunter Laboratory, Department of Chemistry, Clemson University, Clemson, South Carolina 29634-0973, USA. dieterr@clemson.edu
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D002264:Carboxylic Acids / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009570:Nitriles / Q000737:chemistry*; D013454:Sulfoxides / Q000737:chemistry*
D002264:Carboxylic Acids; D009570:Nitriles; D013454:Sulfoxides; D003300:Copper