Reactions of Imidazolio‐Phosphides with Organotin Chlorides: Surprisingly Diverse

Abstract

Dedicated to Professor Dr. Frank Uhlig on the occasion of his 60th birthday.Reactions of primary imidazolio-phosphides ("imidazolylidenephosphinidenes") with R 2 SnCl 2 yield as main products spectroscopically detectable Lewis pairs which undergo base-induced dehydrochlorination in the presence of excess dichlorostannane to afford zwitterionic chloride adducts of distannylated imidazolio-phosphines. In contrast, reactions with R 3 SnCl proceed under dismutation to furnish mixtures containing imidazolium salts and stannylated (oligo)phosphines P(SnR 3 ) 3 and P 7 (SnR 3 ) 3 , respectively. DFT studies were used to rationalize the divergent behavior based on the presumption that the reactions proceed under thermodynamic control and the products observed represent the most stable species under the specific reaction conditions. Computational simulation of selected reaction steps provides a model mechanism for Lewis-acid promoted creation of PP-bonds, which is a prerequisite for oligophosphine formation. The computational studies further highlight parallels between reactions of imidazolio-phosphides with Lewis and Brønsted acids, and allow also to extrapolate the behavior of the P-nucleophiles towards other electrophiles than organotin chlorides.

Trimethyltin(IV) Bearing 3-(4-Methyl-2-oxoquinolin-1(2H)-yl)propanoate Causes Lipid Peroxidation-Mediated Autophagic Cell Death in Human Melanoma A375 Cells

“…The molecular structure of Me3SnL was geometry-optimized at the B3LYP-D3BJ/6-311++G(d,p)(H,C,N,O)/Def2-TZVP(Sn) level of theory (Figure 3a). The same functional was used in the literature to describe the structure and assign the spectra of other organotin compounds [34][35][36][37]. The most important stabilization interactions within the complex are presented in Table S4.…”