Organolithium reagents coupling reactions

The enhanced reactivity of allylic halides and tosylates makes them particularly attractive as electrophiles for Sn2 reactions. Allylic halides are so reactive that they couple with Grignard and organolithium reagents, a reaction that does not work well with unactivated halides. 

As well as alkenylstannanes [106-108], other classes such as a-heteroatom-substituted alkyltributylstannanes [109] and, more importantly, allylic stannanes [110, 111] also undergo these Sn-Cu transmetalations. Otherwise difficult to prepare, allylic copper reagents may, however, be obtained by treatment of allylic stannanes (produced in turn from organolithium, magnesium, or zinc organometallics) with Me2CuLi LiCN. They enter into cross-coupling reactions with alkyl bromides [110] or vinyl triflates (Scheme 2.52) [111]. 

K. Funabiki, T. Kurita, M. Matsui, K. Shibata, An efficient and general entry to (Z)-a-fluoro- -substituted acrylaldehydes based on the coupling reaction of a-fluoro-/t-amino acrylaldehydes with organolithium reagents, Chem. Lett. (1997) 739-740. 

Lithium butyldimethylzincate, 221 Lithium sec-butyldimethylzincate, 221 Organolithium reagents, 94 Organotitanium reagents, 213 Palladium(II) chloride, 234 Titanium(III) chloride-Diisobutylalu-minum hydride, 303 Tributyltin chloride, 315 Tributyl(trimethylsilyl)tin, 212 3-Trimethylsilyl-l, 2-butadiene, 305 Zinc-copper couple, 348 Intramolecular conjugate additions Alkylaluminum halides, 5 Potassium t-butoxide, 252 Tetrabutylammonium fluoride, 11 Titanium(IV) chloride, 304 Zirconium(IV) propoxide, 352 Miscellaneous reactions 2-(Phenylseleno)acrylonitrile, 244 9-(Phenylseleno)-9-borabicyclo[3.3.1]-nonane, 245 Quina alkaloids, 264 Tributyltin hydride, 316 Conjugate reduction (see Reduction reactions)... 

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