2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) is a widely used chiral phosphine ligand, and the sulfonated BINAP is one of the important water-soluble BINAP derivatives. In this article, we report an improved oleum sulfonation method for the synthesis of the high-purity 5,5′-disulfonato-(S)-BINAP ligand with an industrially acceptable high yield. By optimizing the sulfonation conditions and improving the workup process, the yield of 5,5′-disulfonated products was enhanced to 73 %.

Furthermore, an acetonitrile extraction protocol was developed for the purification of sulfonated products by efficiently removing phosphine oxides, by which the content of phosphine oxide can be controlled below 3 %. The structure of 5,5′-disulfonato-(S)-BINAP was characterized with the elemental analysis, FT-IR, ¹H NMR, ¹³C NMR, ³¹P NMR, ¹H-¹H COSY, ¹H-¹³C HSQC, ¹H-¹³C HMBC, and HR-MS, which unambiguously confirmed that the sulfo groups are introduced at the 5,5′-position of the binaphthyl ring skeleton in (S)-BINAP. The prepared high-purity 5,5′-disulfonato-(S)-BINAP was evaluated in the Ru-catalyzed asymmetric hydrogenation of β-keto esters, which exhibited high catalytic activity, enantioselectivity and excellent catalytic stability.

2,2'-双（二苯基膦基）-1,1'-联萘基（BINAP）是一种广泛使用的手性膦配体，磺化BINAP是重要的水溶性BINAP衍生物之一。在本文中，我们报告了一种改进的发烟硫酸磺化方法，用于合成高纯度的5,5'-二磺酸基-（S）-BINAP配体，具有工业上可接受的高收率。通过优化磺化条件并改进后处理工艺，将5,5'-二磺化产物的收率提高到73％。

此外，开发了一种乙腈萃取方案，通过有效去除氧化膦来纯化磺化产物，从而可将氧化膦的含量控制在3％以下。通过元素分析，FT-IR，¹ H NMR，¹³ C NMR，³¹ P NMR，¹ H- ¹ H COSY，¹ H- ¹³ C表征5,5'-二磺酸基-（S）-BINAP的结构HSQC，¹ H- ¹³ C HMBC和HR-MS明确证实了在（S）-BINAP。在Ru催化的β-酮酯不对称加氢反应中评价了制备的高纯度5,5'-二磺基-（S）-BINAP ，具有较高的催化活性，对映选择性和优异的催化稳定性。