Geri Jacob B, Aguilera Ellen Y, Szymczak Nathaniel K
Department of Chemistry, University of Michigan Ann Arbor, 930 N. University, Ann Arbor, MI 48109, USA.
Chem Commun (Camb). 2019 Apr 25;55(35):5119-5122. doi: 10.1039/c9cc01565e.
Difluoromethane (CF2H2) is an ecologically-friendly refrigerant which holds promise as a source of CF2H-. However, the weak acidity (pKa = 35-41) and low stability of the conjugate base have prevented its utilization as a chemical feedstock. In this manuscript, we use a Lewis pair approach to deprotonate CF2H2 and capture CF2H- as R3B-CF2H- adducts. One reagent can be used as a base-free Suzuki reagent in palladium-mediated difluoromethylation, where CF2H- transfer is templated by precoordination to an azaborine derived R3B-CF2H- reagent.
二氟甲烷（CF2H2）是一种生态友好型制冷剂，有望成为CF2H-的来源。然而，其共轭碱的弱酸性（pKa = 35 - 41）和低稳定性阻碍了它作为化学原料的应用。在本论文中，我们采用路易斯酸碱对方法对CF2H2进行去质子化，并捕获CF2H-形成R3B-CF2H-加合物。一种试剂可在钯介导的二氟甲基化反应中用作无碱铃木试剂，其中CF2H-的转移通过预先配位到氮杂硼烷衍生的R3B-CF2H-试剂来实现模板化。
