作者:Richard Böser、Lars Denker、René Frank
DOI:10.3390/molecules24091690
日期:——
cyclo-Cl−B(S2C2H4) as a representative example. Whereas syntheses of three coordinate alkynyl boronate thioesters [R1−C≡C−B(S2X)] proved to be ineffective, the reactions of NHC-adducts (NHC = N-heterocyclic carbene) of cyclo-Cl-B(S2C2H4) afforded the alkyne substituted thioboronate esters in good yield. The products NHC−B(S2C2H4)(C≡C-R1) are remarkably stable towards water and air, which suggests their
炔基官能化硼化合物是药物化学、材料科学和光学材料领域的通用中间体。特别是炔基硼酸酯 [R1-C≡C-B(OR2)2] 是令人感兴趣的,因为它们在炔实体上提供反应性,保留 B-C 键或炔转移到亲电子底物,同时切断后者。由于(i)两个 B-O 键的非凡强度,以及(ii)双官能醇发挥的螯合效应,硼原子通常被很好地稳定。我们推断,将 B-O 替换为 B-S 键会导致所得炔基硼酸酯硫酯 [R1-C≡C-B(S2X)] 具有更高的反应性和后官能化。获得这一类研究不足的化合物从氯二硫代硼烷环-Cl-B(S2C2H4) 开始,作为一个代表性的例子。虽然三配位炔基硼酸酯硫酯 [R1-C≡C-B(S2X)] 的合成被证明是无效的,但环-Cl-B(S2C2H4) 的 NHC-加合物(NHC = N-杂环卡宾)的反应提供了炔烃取代的硫代硼酸酯收率良好。产品 NHC-B(S2C2H4)(C≡C-R1) 对水和空气非