Organoiron- and Fluoride-Catalyzed Phosphinidene Transfer to Styrenic Olefins in a Stereoselective Synthesis of Unprotected Phosphiranes
Organoiron- and Fluoride-Catalyzed Phosphinidene Transfer to Styrenic Olefins in a Stereoselective Synthesis of Unprotected Phosphiranes
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DOI：
10.1021/jacs.9b07069
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发表时间：
2019-08-28
影响因子：
15
通讯作者：
Cummins, Christopher C.
中科院分区：
文献类型：
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作者：
Geeson, Michael B.;Transue, Wesley J.;Cummins, Christopher C.
以二苯并-7-（R）-7-磷杂降冰片二烯（RPA，A = C_（14）H_（10），蒽）和苯乙烯为原料，经催化膦化反应，分别以73%和57%的分离产率合成了反式-1-R-2-苯基膦（R = t-Bu：1-t-Bu; i-Pr：1-i-Pr）。助催化剂体系需要四甲基氟化铵（TMAF）和[Fp（THF）][BF 4]（Fp = Fe（eta（5）-C5 H5）（CO）（2））。在t-Bu衍生物的情况下，使用化学计量反应研究、Hammett分析和氘标记实验来探测反应机理。总之，这些表明铁-膦基FpP（F）（t-Bu）（2）的中间体，其独立地由[Fp（t-BuPA）][BF 4]与TMAF的化学计量反应产生。另外两个可能的反应中间体，[Fp（t-BuPA）][BF 4]和[Fp（1-t-Bu）][BF 4]，独立制备和结构表征。
Catalytic phosphiranation has been achieved, allowing preparation of trans-1-R-2-phenyl-phosphiranes (R = t-Bu: 1-t-Bu; i-Pr: 1-i-Pr) from the corresponding dibenzo-7-(R)-7-phospha-norbornadiene (RPA, A = C14H10, anthracene) and styrene in 73% and 57% isolated yields, respectively. The cocatalyst system requires tetramethylammonium fluoride (TMAF) and [Fp(THF)][BF4] (Fp = Fe(eta(5)-C5H5)(CO)(2)). In the case of the t-Bu derivative, the reaction mechanism was probed using stoichiometric reaction studies, a Hammett analysis, and a deuterium labeling experiment. Together, these suggest the intermediacy of iron-phosphido FpP(F)(t-Bu) (2), generated independently from the stoichiometric reaction of [Fp(t-BuPA)][BF4] with TMAF. Two other plausible reaction intermediates, [Fp(t-BuPA)][BF4] and [Fp(1-t-Bu)][BF4], were prepared independently and structurally characterized.