Oiganolithium reagents

R3T1 compounds, eg, methyl [3003-15A], ethyl [687-82-1], isobutyl [3016-08-8], and phenyl [30034)4-1] thallium(III), are usually prepared by the reaction between a dialkyl or diarylthallium halide and an oiganolithium reagent in ether (16) ... 

A. Rosenthal and S. N. Mikhailov, Branched-chain sugars. Modifications in the reaction of l,2 5,6-di-0-isopropylidene-oi-D-ribo-hexofuranos-3-ulose with Giignard and oiganolithium reagents, J. Carbohydr. Nucleosides Nucleotides 6 237 (1979). 

As described above, the reactions of Grignard or oiganolithium reagents to a-hydroxy or a-amino-carbonyls can proceed with extremely high stereoselectivities (>99 1) when cyclic chelation control is in effect. However, attempts to generate products arising from the C ram-Felkin-Anh mode of addition exclusively have been much less successful. These products are available by the use of conditions which favor nonchelation-controlled processes however, until recently, the selectivities of these reactions (up to 80-90%) never reached those observed in cyclic chelation control additions. 

Feast AAJ, Overend WG, Williams NR (1966) Branched-chain sugars. VI. The reaction of methyl 3, 4-isopropylidene-p-D-erythro-pentopyranosidulose with oiganolithium reagents. J Chem Soc C 303-306... 

If there are no other electrophiles present in the compound, treatment of a chlorophosphine with a Grignard/ oiganolithium reagent has been an effective strategy [265]. Additionally, a copper-catalyzed coupling reaction has successfully used bulky aryl halides [24]... 

Preparation of Functionalized Copper Reagents Starting from Oiganolithium Reagents... 

Each reaction results in addition of one new alkyl group to the carbonyl carbon, and forms one new carbon-carbon bond. The reaction is general for all oiganolithium and Grignard reagents, and works for acetylide anions as well, as illustrated in Equations [l]-[3]. 

Table 6 Acylation of Heterocuprate Reagents Derived from Oiganolithiums and Cuprous r-Butoxide...

Organocopper reagents-Boron tri-fluoride cthcratc, 208 Oiganolithium teagcnts-Coppct(l) halides. 58... 

Butyllithium is an excellent reagent for the dehydrdialogenation of 1-chloroalkenes or 1,1-dichloroal-kanes to terminal alkynes the oiganolithium compound must be added dropwise to avoid alkylation of the intermediate carbenoids, leading to alkenes. Three equivalents of alkyllithium are necessary to convert the 1,1-dichloroalkane to the alkyne (two equivalents from 1-chloroalkenes Scheme 45). 

---