Ylide‐Functionalization via Metalated Ylides: Synthesis and Structural Properties

Abstract

The α‐metallated ylides [Ph3P−C−Z]−M+ (with Z=SO2Tol or CN and M=Na or K) were used as versatile nucleophiles for the facile access to ylide‐substituted compounds. Halogenations, alkylations, carbonylations and functionalization reactions with main group element halides were easily accomplished by simple trapping reactions with the appropriate electrophiles. X‐ray crystallographic studies of all compounds – including the first structures of α‐fluorinated P‐ylides – showed remarkable differences in the ylide backbone depending on the substituents. In the fluorinated compounds, a change from a fully planar to a pyramidalized ylidic carbon centre was observed despite the strongly anion‐stabilizing ability of the yldiide substituent. π‐Donation from the ylide substituent also resulted in geometric restrictions depending on the steric and electronic properties of the introduced substituents.

Phosphorus-ylides: powerful substituents for the stabilization of reactive main group compounds

“…7 ). 63 Although these phosphines have been known for quite some time, 64,65 their strong donor properties owing to the electron donation from the ylide to the phosphorus centre were only recently recognized. Our group used YPhos ligands as electron-rich phosphines in homogeneous catalysis, which led to highly active gold and palladium catalysts e.g.…”

Synthesis, Isolation and Crystal Structures of the Metalated Ylides [Cy3P‐C‐SO2Tol]M (M = Li, Na, K)

“…Until today, only five metalated ylides have been isolated and also structurally characterized (Figure ), whereat only 1‐M and 2‐M (with M = Li, Na, K) have been prepared in gram‐scale and applied in synthesis. For example, our group demonstrated that 1‐M and 2‐M are excellent reagents for ylide‐functionalizations, which represents a powerful tool for the electronic manipulation of main group compounds.,, As such, electron‐deficient species like borenium ions and tetrylenes were successfully isolated starting from 1‐Na . Likewise, a series of ylide‐substituted phosphines were prepared which turned out to be excellent ligands for homogeneous catalysis …”

Synthesis, Crystal and Electronic Structures of a Thiophosphinoyl‐ and Amino‐Substituted Metallated Ylide

“…[5] Since then, a number of metallated ylides (compounds B‐E ) have been isolated [6] – partly also on a gram scale – and applied in ylide transfer reactions. [7] Our group, for example, isolated the sulfonyl‐substituted compounds D and used them for the stabilization of low‐valent main group species [8] as well as in the synthesis of ylide‐substituted phosphines, which revealed themselves to be powerful ligands for homogeneous catalysis. [ 9 , 10 ]…”

“…[5] Since then, a number of metallated ylides (compounds B-E) have been isolated [6] -partly also on a gram scale -and applied in ylide transfer reactions. [7] Our group, for example, isolated the sulfonyl-substituted compounds D and used them for the stabilization of low-valent main group species [8] as well as in the synthesis of ylide-substituted phosphines, which revealed themselves to be powerful ligands for homogeneous catalysis. [9,10] In order to expand the portfolio of readily accessible metallated ylides for their use in main group chemistry, we became interested in the preparation of further readily isolable and storable yldiides.…”