Deprotonation fluoride-promoted

The Pandey group has developed a silver fluoride-promoted desily lation of tertiary bis(silyl)amines as an interesting alternative method to access azomethine ylides (Scheme 2.10).18 Notably, this method allows the generation of nonstabilized azomethine ylides under essentially neutral conditions. The starting materials are prepared by a three-step process, sometimes coupled into a single operation. For example, Boc-protected pyrrolidine 36 can be sequentially deprotonated and silylated twice in a one-pot reaction (Scheme 2.10). Removal of the Boc group and alkylation of the free amine leads to bis(silyl)amine 37. When this compound is treated with 2 equiv of silver fluoride in the presence of phenyl vinyl sulfone, rapid formation of products 39 as single stereoisomers results. 

PPhH)a with CFgC CCFg in the presence of BuLi proceeds with deprotonation of phosphine and fluoride elimination to give (106) a similar base-promoted reaction of Cr(CO)4(PPhH2>2 "with PhC=CCOaEt yields (107). The structure of both was established crystallographically. A similar type of reaction occurs with/ac-Mn(CO)3(PPh2H)2Br. 

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