Alkali Metal Reagents

Review Comprehensive Organic Synthesis, Eds. B. M. Trost and I. Fleming, Pergamon, Oxford (1991), Vol 3, Part 1.6, p 241 

For transition metal-catalyzed cross-coupling of organolithium compounds, see the appropriate transition metal. 

For other ways of generating vinylic lithium reagents, see page 373, Section 9, and page 379, Section 11. 

E+ = RX, RCHO, R2CO, RC02R, RCN, C02 aC02R, RNCO, R3SiCl, R3SnCl 

RX epoxide (BFj-OEt2 or CuCN-2LiCl), RCOC1, RNCO, (PhSe)2, ArSOjF, RjSiCl, ArBr (Pd cat), RCH—CHBr (Pd cat) 

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Grignard reagents usually give poorer yields than do the alkali metal reagents, but some reactions give good yields under Barbier conditions with ultrasonic assistance (Equation (56)).7... 

The molecule Ceo was first observed in the mass spectrum of laser evaporated carbon by Kroto et al., who proposed the now familiar soccer ball stmcture. Subsequently, macroscopic quantities were synthesized. In the solid state, Ceo adopts a face-centered cubic (fee) stmcture, which can be considered to be based on the close packing of spheres with a radius of 5 A. Two tetrahedral sites and one octahedral site with radii 1.12 and 2.06 A are present in the stmcture. The availability of these empty sites and the electronegativity of Ceo make it a suitable host lattice for reductive intercalation by electropositive cations such as the alkah metals. The octahedral site is larger than any of the alkah cations, but the tetrahedral site is about the same size as Na+. The discovery of Superconductivity in K Ceo (Tc = 18K) has focused considerable interest on these materials. Intercalation compounds can be prepared by direct reaction of the alkali metal with Ceo to form compositions Aj,C6o (x = 2, 3, 4, or 6) depending on the specific A cation. Direct reaction of Ceo with the alkali metals is the most conveiuent route to the AeCeo phases other compositions can be prepared by use of the appropriate stoichiometry or by reaction of AeCeo with Ceo. Other alkali metal reagents such as NasHg2 and NaH have also been used. ... 

Formation of Silicon-Transition and Inner Transition-Metal Bond 243 S.8.3.4. from Silyl-Alkali Metal Reagents... 

I. from Germyl-Alkali-Metal Reagents with Group-IIB Halides and Organohalldes. 

Organogermyl-alkali-metal reagents are powerful nucleophiles and can establish bonds with Zn, Cd and Hg, e.g., to form a Ge—Zn compound ... 

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