Preparation via Sterically Promoted SN2’ Substitution and Structural Characteristics of a Mes*-Substituted Tertiary Ethynylphosphine
Preparation via Sterically Promoted SN2’ Substitution and Structural Characteristics of a Mes*-Substituted Tertiary Ethynylphosphine
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通过空间促进的 SN2 取代制备 Mes* 取代的叔乙炔基膦的结构特征
DOI：
10.1002/hc.21182
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
K. Mikami
中科院分区：
文献类型：
--
作者：
S. Ito;M. Nanko;K. Mikami
空间位阻的2-溴-3-硅氧基磷丙烯[(Z)-Mes*-P=C(BrCH)CH(OSiMe3)Mes；Mes*=2，4，6-tBu3C6H2，Mes=2，4，6-Me 3C6H2]与丁基锂通过烷基锂的SN2‘反应和随后的HBr的β消除反应生成了大体积的乙炔基膦[Mes*P(NBu)C≡CME]。均三甲苯基团的空间位阻会引起轨道控制反应和卤素-金属交换的抑制。从空间位阻和立体化学的角度讨论了新型乙炔基膦的结构特征。根据密度泛函理论计算，进一步讨论了MES芳环的显著扭曲现象。
The reaction of a sterically encumbered 2‐bromo‐3‐silyloxyphosphapropene [(Z)‐Mes*‐P = C(Br)CH(OSiMe3)Mes; Mes* = 2,4,6‐tBu3C6H2, Mes = 2,4,6‐Me3C6H2] and butyllithium afforded a bulky ethynylphosphine [Mes*P(nBu)C≡CMes] via SN2′ reaction of the alkyllithium and subsequent beta‐elimination of HBr. The orbital‐controlled reaction and prohibition of the halogen–metal exchange would be induced by the steric encumbrance of the mesityl group. Structural characteristics of the novel ethynylphosphine were also discussed in views of steric encumbrance as well as stereochemistry. The remarkable distortion of Mes* aromatic ring was further discussed according to DFT calculations.