Methyl lithium, with

C. Alkyl and Aryl Derivatives.—Reactions of organometallic reagents, such as methyl-lithium, with fluorocyclophosphazenes are, in general,... 

A second approach involves a nucleophilic attack on the metal. This is seen in the reaction of methyl lithium with tungsten(V ) chloride ... 

When carbon monoxide is bonded to a transition element, in a positively charged or even uncharged compound, the electrophilic capacity of carbon increases compared with the isolated molecule. Examples of nucleophilic attack are in equations (4) and (5). The reaction of methyl-lithium with W(CO)e giving the anioiuc acyl complex of equation (4a) is followed by alkylation to the carbene derivative of equation (4b). The formation of a carbamoyl complex with m-PtCl2(CO)2 is shown in equation (5). 

The reactions of strong carbon nucleophiles with arene oxides 1 and 11 leads to rapid adduct formation.Methyl lithium and dimethyl magnesium react with arene oxide 1 by 1,6-addition to give ds-adducts. Trans-adducts were also obtained from reaction of dimethyl magnesium and methyl lithium with arene oxides 1 and 11, respectively, by the more usual 1,2-trans addition mechanism. ... 

The [(phenylthio)methyl]hydridosilanes la/lb used as bifunctional assembling ligands were prepared by the reaction of [(phenylthio)methyl]lithium with the corresponding chlorosilanes, similar to the synthesis of dimethyl[(phenylthio)methyl]silane [3a] and diphenylbis[(phenylthio)methyl]silane [3b],... 

Recently there has been interest in the synthesis of analogs of the naturally occurring mono- and diphosphate group. Corey and Volante ° have reported the alkylation of (dimethylphosphoryl)methyl-lithium with, for example, geranyl, famesyl and 3-methyl-2-butenyl bromides. Tlie products were assessed for their ability to inhibit the biosynthesis of squalene. McClard and coworkers described the alkylation of the phosphonylphosphinyl anion (14) to yield the P—C— P—C compounds, proven enzyme inhibitors (Scheme 13). The free acid derivatives were obtained by treatment of the alkylated products with bromotrimethylsilane. 

Experiments with mono- and bi-cyclic ketones show that methyl-lithium with lithium dimethylcuprate gives methyl carbinols, very largely with the axial-hydroxy... 

The reagent is prepared1 by the reaction in ether of 3 equivalents of methyl-lithium with 1 equiv. of ferrous iodide (—20°, N2 atmosphere). The reagent decomposes appreciably upon storage at 0° for several hours. 

The Se2 Reaction. In electrophilic substitution, the substrate is usually an organometallic reagent, for which we can use methyllithium as the simplest version. We saw the low-energy orbitals of methyl-lithium with and without hybridisation in Fig. 1.64. The frontier orbitals for the SE2 reaction will be the HOMO of the nucleophile (the strongly associated with C—M bonding) and the LUMO of the electrophile, modelled in Fig. 5.3 by an empty p orbital. In this case,457 the frontier orbital interaction (Fig. 5.3) can be bonding for attack on either side of the carbon atom. 

Ketene 0,5-acetal derivatives can be readily prepared from the reaction of [methoxy(phenylthioXtrimethylsilyl)methyl]lithium with aldehydes and ketones108 (equation 103). It is interesting to point out that the methyl enol ether was converted to the enol silyl ether by reaction with trimethyliodosilane. This was then hydrolyzed to the thio ester 53 (equation 104). 

Recendy, the potential for beryllium insertion into C—N bonds of NHCs has been investigated by Arrowsmith et al. [42]. Reaction of 2 equivalents of methyl lithium with 1 equivalent of both ber)dlium chloride and the NHC (IPr) resulted in the formation of the methylberjdliumhydride-IPr dimer (Figure 15.12), similar to that of the diphenylber)dlium-NHC complex mentioned earlier. 

The reactions of methyl-lithium with the hexacarbonyls [M(CO)6] (M = Cr, Mo, or W) and the derivatives [ML(CO)5] have been studied using stopped-flow techniques. The reactions obey the rate law... 

Full details have appeared of the a-oxo-lithiation of 2,6-disubstituted benzoate esters (6) having sterically protected carbonyl groups (c/. 3,133). Reaction of the lithio derivatives, formed from (6) by reaction with excess base or regenerated from the stannane (7) by treatment with stoicheiometric methyl-lithium, with alkyl halides or carbonyl compounds followed by ester cleavage leads to alcohols and diols, respectively (Scheme 9). 

Table 1 Reactions of [bis(2-pyridyldimethylsilyl)methyl]lithium with carbonyl compounds ...

Reaction of [bis(2-pyridyldimethylsilyl)methyl]lithium with Carbonyl Compounds. The Peterson-t)fpe reaction of [bis(2-pyridyldimethylsilyl)methyl]lithium with primary, secondary, and tertiary aliphatic and aromatic aldehydes produces the corresponding 2-pyridyl-suhstituted vinylsilanes in essentially quantitative yields (entries 1-7, Table 1, eq 3). The reaction is also applicable to sterically hindered aldehydes (entries 3 and 6) and di-aldehyde (entry 7). The reactions with ketones give disubstituted vinylsilanes with somewhat lower yields (entries 8-10). The reaction can be applied to the stereoselective synthesis of dienylsilanes as well (entries 11-13). In all cases, the reaction occurs in a complete stereoselective fashion (>99% E). 

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