Organolithium reagents functionalized

Functionalized organolithium reagents can be prepared and alkylated. The configuration of the dioxanyl reagent 2 proved to be subject to control.85 The kinetically favored trans lithio derivative is converted to the more stable cis isomer at 20° C. Both isomers were methylated with retention of configuration at saturated carbon. 

Scheme 2.38 Functionalized allenes formed by 1,4-addition of organolithium reagents to enynes and electrophilic trapping with aldehydes (111, 112) ketones (113,114), ethylene oxide (115) and carbon dioxide (116).

The use of sterically hindered secondary organolithium reagents, such as (CgH jCH Li, drastically favors the O-alkyl scission of thejbster group (37) finally, organolithium compounds leading to non enolizable keto functions in the first step of substitution, such as C H Li, promote competitive and consecutive reactions resulting in complex copolymers of poorly defined structure (38,39) ... 

Many functional groups are incompatible with organolithium reagents. Execution of transmetalations at very low temperatures, however, enables functionalized... 

Methylmagnesium N-cyclohexyliso-propylamide, 189 with organolithium reagents f-Butyllithium, 58 Lithium acetylide, 44 with functionalized carbon reagents Alkyldimesitylboranes, 8 Di- x-carbonylhexacarbonyIdicobalt, 99... 

Acyliron complexes have found many applications in organic synthesis [40]. Usually they are prepared by acylation of [CpFe(CO)2] with acyl chlorides or mixed anhydrides (Scheme 1.13). This procedure affords alkyl, aryl and a,P-unsaturated acyliron complexes. Alternatively, acyliron complexes can be obtained by treatment of [Fe(C5Me5)(CO)4]+ with organolithium reagents, a,P-Unsaturated acyliron complexes can be obtained by reaction of the same reagent with 2-alkyn-l-ols. Deprotonation of acyliron complexes with butyllithium generates the corresponding enolates, which can be functionalized by reaction with various electrophiles [40]. 

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