Bridging the Gap between Bisylides and Methandiides: Isolation, Reactivity, and Electronic Structure of an Yldiide

Abstract

Bisylides and methandiides are two unique families of carbon bases that have found a variety of applications in recent years. Metalated ylides (yldiides) are the link between these types of compounds. Yet, only little is known about their properties, reactivities, and particularly their electronic structure. Here, we report the preparation of the metalated ylide [Ph3P-C-SO2Tol](-) (1) with different alkali metal counterions. The compounds have been studied by X-ray diffraction analysis and NMR spectroscopy and the first structures of a sodium and potassium yldiide are presented. The electronic structure of 1 was explored by DFT calculations confirming its relation with other divalent carbon species. Reactivity studies demonstrate the strong nucleophilicity of the yldiide and its capability to act both as a σ- and π-donor.

Isolation of the Metalated Ylides [Ph3P−C−CN]M (M=Li, Na, K): Influence of the Metal Ion on the Structure and Bonding Situation

“…To display multiplicities and signal forms correctly the following abbreviations were used: s=singlet, d=doublet, t=triplet, m=multiplet, br=broad signal. Signal assignment was supported by DEPT, APT, HSQC and HMBC experiments and by literature studies on similar compounds . NMR spectra of all compounds are depicted in the Supporting Information.…”

“…Despite their huge synthetic potential, very little is known about their electronic structures. Only four yldiides have been isolated and structurally authenticated so far . In this regard, yldiide 1 seemed to be especially interesting because it can be viewed as an anionic carbone, in which the carbon atom is coordinated like a metal in a cyanido‐phosphine complex (Figure ).…”

Metalated Ylides: A New Class of Strong Donor Ligands with Unique Electronic Properties

“…22 Interestingly, the metalated ylide 2 was not prepared via a classical deprotonation reaction analogous to 1 but via a 1,2-carbometalation reaction of carbene 5 with butyllithium. The structure of the silyl-substituted compound (Figure 3, left) featured a planar geometry around the ylidic carbon atom with short P–C [1.636(11) Å] and Si–C [1.755(10) Å] distances.…”

Using Ylide Functionalization to Stabilize Boron Cations

“…Our group has become interested in the coordination chemistry of ylidic donor ligands. Particularly, metalated ylides with two lone pairs of electrons at the central carbon atom seemed to be ideal ligands for the stabilization of electron‐deficient species due to their potential ability to function as carbon‐centered σ‐ and π‐donor ligands . Herein, we challenged this donor capacity of metalated ylides and their applicability as a novel class of X,L‐type ligands for the stabilization of cationic boron species.…”

“…For the preparation of an ylide‐stabilized boron cation we chose a synthetic strategy via hydride abstraction from the bis(ylide)‐functionalized borane 1 (Scheme ). 1 is conveniently accessible from the metalated ylide YNa [Y=(Ph 3 PCSO 2 Tol) − ] and BH 3 ⋅THF . To access the corresponding boron cation a solution of 1 in CHCl 3 was treated with one equiv.…”