Mechanism of the Gold(I)-Catalyzed Rautenstrauch Rearrangement: A Center-to-Helix-to-Center Chirality Transfer

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• 作者：Olalla Nieto Faza ; Carlos Silva L&oacute ; pez ; Rosana Á ; lvarez ; and Angel R. de Lera
• 刊名：Journal of the American Chemical Society
• 出版年：2006
• 出版时间：February 22, 2006
• 年：2006
• 卷：128
• 期：7
• 页码：2434 - 2437
• 全文大小：206K
• 年卷期：v.128,no.7(February 22, 2006)
• ISSN：1520-5126

文摘

The mechanism of the stereospecific gold(I)-catalyzed Rautenstrauch rearrangement of (E)-1-ethynyl-2-methyl-but-2-en-yl acetate to 3,4-dimethyl-cyclopent-2-enone has been computationally addressedusing DFT (B3LYP/6-31G*, SDD for Au). Our results indicate that the bond formation event follows theAu(I)-induced acetyl transfer to the vicinal alkyne and that it is the helicity of the pentadienyl cationintermediate which keeps memory of the chiral information. The fidelity of the center-to-helix-to-center chiralitytransfer requires that the rates of helix interconversion and pivaloyl rotation are slower than the cyclization,as calculations predict.