Dimerization and Cycloaddition Reactions of Transient Tri- tert -butylphosphacyclobutadiene Generated by Lewis Acid Induced Isomerization of Tri- tert -butylphosphatetrahedrane
Dimerization and Cycloaddition Reactions of Transient Tri- tert -butylphosphacyclobutadiene Generated by Lewis Acid Induced Isomerization of Tri- tert -butylphosphatetrahedrane
复制标题
路易斯酸诱导磷酸三叔丁基四面体异构化生成瞬时三叔丁基磷环丁二烯的二聚和环加成反应
DOI：
10.1021/jacs.1c06840
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发表时间：
2021
影响因子：
15
通讯作者：
Cummins, Christopher C.
中科院分区：
文献类型：
--
作者：
Riu, Martin-Louis Y.;Eckhardt, André K.;Cummins, Christopher C.
三叔丁基磷杂四氢吡喃（1）在刘易斯酸或过渡金属络合物存在下，可作为异构体三叔丁基磷杂环丁二烯的合成子。当与亚化学计量量的三苯硼烷结合时，化合物1以72%的分离产率形成三叔丁基磷环丁二烯的梯烷型二聚体。通过在过量苯乙烯（20当量）或乙烯（1大气压）存在下重复该实验来实现所产生的中间体的捕获，并且分别以88%和74%的产率分离出三叔丁基磷杂环丁二烯的相应[4 + 2]环加合物。铂配合物（Ph_3 P）_2Pt（C_2H_4）也与1反应生成三叔丁基磷杂环丁二烯的橙子η_2配合物，分离产率为80%。此外，我们报告了一种新的方法，通过氟化物诱导的三甲基甲硅烷基氟消除产生的膦类物质，导致改进的制备程序为1（182毫克，33%的分离收率）。
Tri-tert-butylphosphatetrahedrane (1) is shown here to act as a synthon of isomeric tri-tert-butylphosphacyclobutadiene in the presence of a Lewis acid or transition-metal complex. When it is combined with a substoichiometric amount of triphenylborane, compound1forms a ladderane-type dimer of tri-tert-butylphosphacyclobutadiene in 72% isolated yield. Trapping of a generated intermediate was achieved by repeating the experiment in the presence of excess styrene (20 equiv) or ethylene (1 atm), and the corresponding [4 + 2] cycloadducts of tri-tert-butylphosphacyclobutadiene were isolated in 88% and 74% yields, respectively. The platinum complex (Ph3P)2Pt(C2H4) also reacts with1to form an orange η2complex of tri-tert-butylphosphacyclobutadiene in 80% isolated yield. Additionally, we report a novel method for generating a phosphinidenoid species via fluoride-induced trimethylsilyl fluoride elimination, leading to an improved preparative procedure for1(182 mg, 33% isolated yield).