Vermersch François, Yazdani Sima, Junor Glen P, Grotjahn Douglas B, Jazzar Rodolphe, Bertrand Guy
UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093-0358, USA.
Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182-1030, USA.
Angew Chem Int Ed Engl. 2021 Dec 20;60(52):27253-27257. doi: 10.1002/anie.202111588. Epub 2021 Nov 18.
A simple experimental procedure for scaling carbene Brønsted basicity is described. The results highlight the strong basicity of pyrazol-4-ylidenes, a type of mesoionic carbene, also named cyclic-bentallenes (CBA). They are more basic (pK >42.7 in acetonitrile) than the popular proazaphosphatrane Verkade bases, and even the Schwesinger phosphazene superbase P ( Bu). The basicity of these compounds can readily be tuned, and they are accessible in multigram quantities. These results open new avenues for carbon centered superbases.
描述了一种用于衡量卡宾布朗斯特碱度的简单实验方法。结果突出了吡唑 - 4 - 亚基（一种内盐型卡宾，也称为环状弯曲烯（CBA））的强碱性。它们比常用的前氮杂环磷烷Verkade碱甚至施韦辛格磷腈超强碱P（Bu）碱性更强（在乙腈中pK>42.7）。这些化合物的碱度可以很容易地调节，并且可以以多克量获得。这些结果为以碳为中心的超强碱开辟了新途径。
