Is the A-ring of sparteine essential for high enantioselectivity in the asymmetric lithiation-substitution of N-Boc-pyrrolidine?

PW Phuan, JC Ianni, MC Kozlowski

Index: Phuan, Puay-Wah; Ianni, James C.; Kozlowski, Marisa C. Journal of the American Chemical Society, 2004 , vol. 126, # 47 p. 15473 - 15479

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Citation Number: 38

Abstract

The simplest chiral portion of sparteine, N, N'-dimethyl-2-endo-methylbispidine, was prepared and evaluated in the asymmetric lithiation-substitution of N-Boc-pyrrolidine. The results indicate that the complete A-ring of sparteine is essential for high levels of asymmetric induction. DFT-QSSR analyses of the diamine/Li+ complexes and DFT calculations of the pertinent i-PrLi/diamine/N-Boc-pyrrolidine complexes are predictive ...