Wong Lawrence W Y, Kan Jack W H, Sung Herman H Y, Williams Ian D
Department of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People's Republic of China.
Acta Crystallogr C Struct Chem. 2017 Aug 1;73(Pt 8):625-631. doi: 10.1107/S2053229617009718. Epub 2017 Jul 21.
Spiroborate anions have potential for crystallization or resolution and chiral bis(mandelato)borate anions can be used for the efficient resolution of a diverse range of racemic cations via diastereomeric salt formation. The syntheses, X-ray crystal structures and solubilities of three chiral bis(mandelato)borate salts, namely poly[[aqua-μ-bis[(R)-mandelato]borato-lithium(I)] monohydrate], [Li(CHBO)(HO)] or Li[B(R-Man)]·HO, (1), ammonium bis[(R)-mandelato]borate, NH·CHBO or NH[B(R-Man)], (2), and tetra-n-butylammonium bis[(R)-mandelato]borate, CHN·CHBO or NBu[B(R-Man)], (3), are reported. They all have a B configuration and show a reasonably well-conserved anion geometry. The main conformational variation is the orientation of the two phenyl groups, supporting the idea that [B(Man)] is a semi-rigid anion. The salts are differentially soluble in a range of solvents, meaning they could be useful as reagents for resolution via a metathesis crystallization approach.
螺硼酸根阴离子具有结晶或拆分的潜力，手性双（扁桃酸根）硼酸根阴离子可通过非对映体盐的形成，用于多种外消旋阳离子的有效拆分。本文报道了三种手性双（扁桃酸根）硼酸盐，即聚[[水合-μ-双[(R)-扁桃酸根]硼酸根锂(I)]一水合物]，[Li(CHBO)(HO)]或Li[B(R-Man)]·HO，(1)、双[(R)-扁桃酸根]硼酸铵，NH·CHBO或NH[B(R-Man)]，(2)，以及四正丁基铵双[(R)-扁桃酸根]硼酸盐，CHN·CHBO或NBu[B(R-Man)]，(3)的合成、X射线晶体结构和溶解度。它们均具有B构型，且阴离子几何结构相当保守。主要的构象变化是两个苯基的取向，这支持了[B(Man)]是一种半刚性阴离子的观点。这些盐在一系列溶剂中的溶解度不同，这意味着它们可用作通过复分解结晶方法进行拆分的试剂。
