An Investigation of the Solid-State Photochemistry of α-Mesitylacetophenone Derivatives: Asymmetric Induction Studies and Crystal Structure–Reactivity Relationships
作者:Eugene Cheung、Katja Rademacher、John R. Scheffer、James Trotter
DOI:10.1016/s0040-4020(00)00496-8
日期:2000.9
a series of α-mesitylacetophenone derivatives into 2-indanols via δ-hydrogen abstraction has been investigated in the solid state. A correlation between solid-state reactivity and crystal structure has been established for this type of reaction. For the seven compounds whose crystal structures were determined, the average value of d (CO⋯H distance) and L (CO⋯CH3 distance) were 2.77±0.04 Å and 3.42±0
在固态下研究了一系列经由δ-氢提取的α-间苯二甲酰苯乙酮衍生物的光化学转化为2-茚满醇的过程。对于这种类型的反应,已经建立了固态反应性和晶体结构之间的相关性。对于七个已确定晶体结构的化合物,d(CO⋯H距离)和L(CO⋯CH 3距离)的平均值分别为2.77± 0.04Å和3.42± 0.06Å ,ω的平均值(δ-H平面外角),Δ(CO⋯H角)和θ(C–H⋯O角)分别为59±2°,80±7°和123±3°。这些参数主要取决于羰基与异丁烯环上完全二等分位置的偏差的大小,在固态反应性酮的情况下,偏差范围为9–14°,对于未反应的化合物,偏差范围为0°。通过为反应物提供羧酸取代基来进行不对称诱导研究,羧酸取代基通过与旋光性胺形成盐而与离子性手性助剂连接。结晶状态下的盐(总共13种)的辐射使对映体过量高达90%。确定了三种盐的晶体结构,并在此基础上讨论了在结晶状态下选择性的原因。