The iso-VAPOL ligand: synthesis, solid-state structure and its evaluation as a BOROX catalyst
作者:Anil K. Gupta、Xin Zhang、Richard J. Staples、William D. Wulff
DOI:10.1039/c4cy00742e
日期:——
and it is found that all three ligands have the cisoid conformations in the solid-state; the dihedral angle between the two aryl groups is less than 90°. In addition, all three ligands pack in the solid-state with no inter-molecular hydrogen bonds. This is the opposite to what has been reported for BINOL where all known structures exist with transoid conformations where the dihedral angle is >90° and
新的拱形联芳基配体iso-VAPOL是VAPOL的异构体,但具有VANOL的手性口袋。iso-VAPOL的合成涉及类似于VAPOL的环加成/电环化级联(CAEC),不同之处在于iso-VAPOL的起始原料成本不到其十分之一。确定了iso-VAPOL的固态结构以及VANOL的固态结构,因为以前没有报道过。将iso-VAPOL和VANOL的结构与VAPOL的已知固态结构进行了比较,发现所有三个配体在固态中均具有顺式构象。两个芳基之间的二面角小于90°。另外,所有三个配体都以固态堆积,没有分子间氢键。这与关于BINOL的报道相反,在BINOL中,所有已知的结构都存在具有反式构象的二面角> 90°,并且BINOL单元在相邻BINOL单元之间带有氢键。光谱证据包括给出的1 H和11 B NMR光谱表明,异VAPOL配体将以与B(OPh) 3形成BOROX催化剂的方式与以前通过光谱法和X射线晶体学报道