Characterization of a boron-stabilized carbanion, tris(trimethylenedioxyboryl)methide ion, and its reactions with carbonyl compounds
作者:D.S. Matteson、Leon A. Hagelee
DOI:10.1016/s0022-328x(00)94140-8
日期:1975.7
−C[BO2(CH2)3]3 (II), which has been isolated and characterized. The IIB NMR spectrum of II in hexamethylphosphoramide consists of one peak 1.05 ppm downfield from boron trifluoride etherate. The 1H NMR spectrum of II after solvolysis in protic solvents shows that the B-butyl group has been cleaved off to the extent of 90–100%, presemably as the butaneboronic ester III. The identity of II has been further checked
在-70°C在四氢呋喃中,将丁基锂加到四(三亚甲基二氧基硼基)甲烷C [BO 2(CH 2)3 ] 4(I)中,沉淀出三(三亚甲基二氧基硼基)甲基化锂。李+ - C [BO 2(CH 2)3 ] 3(II),它已被分离和表征。六甲基磷酰胺中II的II B NMR光谱由来自三氟化硼醚化物的低场一个1.05 ppm峰组成。在1在质子溶剂节目溶剂分解后II的1 H NMR光谱,所述乙丁基的裂解程度为90–100%,大概是丁烷硼酸酯III。通过将其转化为已知的三苯基锡衍生物VI和溴衍生物XI,进一步检查了II的身份,如果在与溴反应之前未分离出II,则很难纯化。对于与醛和酮的缩合,II不能方便地由I与甲基锂生成,也不能分离,并且可以高收率获得烯烃1,1,1-二硼酸酯XII和XIV。多聚甲醛(XII,R = H)的缩合产物与环戊二烯和全氯环戊二烯进行Diels-Alder反应,并简要研究了苯甲醛衍生物XII(R