Ylide‐Functionalization via Metalated Ylides: Synthesis and Structural Properties

摘要

The α‐metallated ylides [Ph 3 P?C?Z] ? M + (with Z=SO 2 Tol 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. Put ylide on it : The α‐metallated ylides 1‐Na and 2‐K are versatile reagents for the facile synthesis of ylide‐substituted compounds with most different substituents, including α‐fluoroylides. The ylide moiety sensitively responds to the electronic and steric properties of the groups it is bound to. These changes can be followed by NMR spectroscopy and crystallography.