Mechanochemical Influence on the Stereoselectivity of Halide Metathesis: Synthesis of Group 15 Tris(allyl) Complexes

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• 作者：Nicholas R. Rightmire ; David L. Bruns ; Timothy P. Hanusa ; William W. Brennessel
• 刊名：Organometallics
• 出版年：2016
• 出版时间：June 13, 2016
• 年：2016
• 卷：35
• 期：11
• 页码：1698-1706
• 全文大小：470K
• 年卷期：0
• ISSN：1520-6041

文摘

The stereochemical outcomes of reactions conducted in solution and those under mechanochemical conditions need not be the same; this is a well-established observation in organic synthesis, but few examples are known in organometallic systems. Halide metathesis is now shown to be a type of mechanochemical reaction that can produce different ratios of stereoisomers depending on whether the reagents are dissolved or ball-milled. Trihalides of As (X = I), Sb (X = Cl), and Bi (X = Cl) react with K[A′] (A′ = 1,3-(SiMe₃)₂C₃H₃) (As, Sb) or [AlA′₃] (Bi) to generate the tris(allyl) complexes [EA′₃]. All three complexes are found in two diastereomeric forms of C₁ (R,S,S) and C₃ (R,R,R) symmetry, and mechanochemical synthesis increases the C₁:C₃ ratio relative to that produced in hexanes solution (up to 3.3× in the case of [AsA′₃]). The stereoselectivity of the metathesis in the solid state can be correlated with the asymmetric environment found in the group 15 trihalides; mechanochemical induction provides a new tool for influencing this important class of synthetic reactions.