Organolithium compounds with sulfonates

Recently, the reaction of organolithium compounds with magnesium carboxylates or sulfonates has been used to prepare organomagnesium compounds with increased selectivity towards carbonyl compounds (see Section 6.1) [32],... 

Piperine (25) [56] and trichonine (13) [57] have been prepared by reaction of the corresponding a-sulfonyl organolithium compound with N-(4-oxobutanoyl)piperidine and pyrrolidine, respectively, followed by acetylation of the resulting (3-hydroxy sulfone and final base-promoted double elimination (Scheme 13). Using 4-oxobutanoic ethyl ester, this methodology has been applied to the synthesis of dodecatetraeneamide (19) [23],... 

Grignard reagents convert aromatic sulfonyl chlorides or aromatic sulfonates to sulfones. Aromatic sulfonates have also been converted to sulfones with organolithium compounds.1745 Vinylic and allylic sulfones have been prepared by treatment of sulfonyl chlorides with a vinylic or allylic stannane and a palladium-complex catalyst.1746 Alkynyl sulfones can be prepared by treatment of sulfonyl chlorides with trimethylsilylalkynes, with an AICL catalyst.1747... 

Likewise, the first step in the synthesis of 50 is a regioselective ring opening of epoxide 40 with organolithium compound 45. By a series of manipulations, sulfone 47c is produced in 50% overall yield with 97% ee [11]. Ring opening of lactone 48 with the lithiated sulfone 47c... 

The simplest procedure for the sulfonation of polymeric organolithium compounds is the direct reaction with sultones. Thus, the functionalization of PSLi (Ain = 2.7 -4.7 X lO gmol" ) with generally a twofold molar excess of 1,3-propane sultone (eqn [23]) was investigated as a function of solvent and temperature. At temperatures from 3 to 80 ° C in benzene solution. 

Another dramatic example of the usefulness of DPE end-capping of polymeric organolithium compounds to promote efficient functionalization reactions is the sulfonation reaction using sultones [142]. A careful examination of the functionalization of poly(styryl)lithium with 1,3-propane sultone showed that the corresponding sulfonated polymer (see Eq. 32) was obtained in maximum yields of only 30% and 53% in benzene or tetrahydrofuran, respectively [142] ... 

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