Jakhar Vineet K, Esper Alec M, Ghiviriga Ion, Abboud Khalil A, Ehm Christian, Veige Adam S
Department of Chemistry, University of Florida, Center for Catalysis, P.O. Box 117200, Gainesville, FL 32611, USA.
Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126, Napoli, Italy.
Angew Chem Int Ed Engl. 2022 Jul 25;61(30):e202203073. doi: 10.1002/anie.202203073. Epub 2022 Jun 7.
The reactivity of phosphaalkynes, the isolobal and isoelectronic congeners to alkynes, with metal alkylidyne complexes is explored in this work. Treating the tungsten alkylidyne [ BuOCO]W≡C Bu(THF) (1) with phosphaalkyne (10) results in the formation of [O C( BuC=)W{η -(P,C)-P≡C-Ad}(THF)] (13- Bu ) and [O C(AdC=)W{η -(P,C)-P≡C- Bu}(THF)] (13-Ad ); derived from the formal reductive migratory insertion of the alkylidyne moiety into a W-C bond. Analogous to alkyne metathesis, a stable phosphametallacyclobutadiene complex [ BuOCO]W[κ -C( Bu)PC(Ad)] (14) forms upon loss of THF from the coordination sphere of either 13- Bu or 13-Ad . Remarkably, the C-C bonds reversibly form/cleave with the addition or removal of THF from the coordination sphere of the formal tungsten(VI) metal center, permitting unprecedented control over the transformation of a tetraanionic pincer to a trianionic pincer and back. Computational analysis offers thermodynamic and electronic reasoning for the reversible equilibrium between 13- Bu/Ad and 14.
本工作研究了磷炔（炔烃的等瓣体和等电子类似物）与金属亚烷基配合物的反应活性。用磷炔（10）处理钨亚烷基配合物[BuOCO]W≡C Bu(THF)（1），会生成[O C(BuC=)W{η -(P,C)-P≡C-Ad}(THF)]（13 - Bu）和[O C(AdC=)W{η -(P,C)-P≡C - Bu}(THF)]（13 - Ad）；这是通过亚烷基部分向W - C键的形式上的还原迁移插入反应得到的。与炔烃复分解类似，在13 - Bu或13 - Ad的配位球中失去THF后，会形成稳定的磷金属环丁二烯配合物[BuOCO]W[κ - C(Bu)PC(Ad)]（14）。值得注意的是，C - C键会随着从形式上的钨（VI）金属中心的配位球中添加或去除THF而可逆地形成/断裂，从而实现了对四阴离子钳形物向三阴离子钳形物转化及再转化的前所未有的控制。计算分析为13 - Bu/Ad与14之间的可逆平衡提供了热力学和电子学方面的解释。
