constants [K=anti/syn] of a pair of atropisomers due to restrictedrotationabout Csp3–Csp2 bond for [2-(2-hydroxynaphthalen-1-yl)-3,3-dimethylindolin-1-yl](4-substituted phenyl)methanone were determined in some solvents. The presence of the effective π–π interaction was demonstrated by the correlation between the equilibrium constants (K) and the substituent effect of the phenyl groups (σp), suggesting that
由于[2-(2-(2-羟基萘-1-基)-3,3-二甲基吲哚-1-基]围绕Csp 3 -Csp 2键的旋转受限制而导致的一对阻转异构体的平衡常数[ K = anti / syn ]在某些溶剂中测定了(4-取代的苯基)甲酮。有效的π-π相互作用的存在通过平衡常数(K)和苯基的取代基效应(σp)之间的相关性证明,表明“中性型”相互作用是有效的。
Role of 2-Naphthyl Ether Intermediate in Formation of Isolable Atropisomers Derived from the Coupling Reaction of (2-Hydroxy-3,3-dimethylindolin-1-yl)(substituted Phenyl)methanones with 2-Naphthol
The formation pathway of the atropisomers derived from the reaction of (2-hydroxy-3,3-dimethylindolin-1-yl)(4-substituted phenyl)methanones with 2-naphthol in the presence of BF(3)center dot Et(2)O was discussed on the basis of the isolation of the 2-naphthyl ether intermediate whose structure was determined by single crystal X-ray analysis, The results indicate that the coupling reaction proceeds through stepwise mechanism, i.e., the ether intermediate formation followed by Fries-type rearrangement.
Leuchs et al., Chemische Berichte, 1932, vol. 65, p. 1586,1589