Vinyltin reagent

Vinylic halides can also be coupled " with Zn—NiCli, with vinyltin reagents and a palladium catalyst, and with n-BuLi in ether in the presence of MnCl2. 

Other organometallic compounds add to isocyanates. Vinyltin reagents lead to conjugated amides. ... 

Coupling of vinyl halides with vinyltin reagents. This cross-coupling can be effected at room temperature in DMF in the presence of (CH,CN)2PdCl, or CLPd[P(C6H5),]2. Pure (E,E)-, (E,Z)-, (Z,E)-, or (Z,Z)-1,3 dienes can be prepared by this reaction, since the geometry of each partner is retained. The reaction tolerates many functional groups. 

Cross-coupling of allyl halides with vinyltin reagents. Allyl halides couple with vinyl- or aryltin reagents in the presence of this catalyst in uniformly high yields (>80%). A wide variety of functional groups is tolerated. The geometry of the double bond in both partners is retained, but the carbon-to-carbon bond is formed with inversion at the allylic position. 

Vinylic halides can be coupled to give 1,3-butadienes (134) by treatment with activated copper powder in a reaction analogous to the Ullmann reaction (13-11). " This reaction is stereospecific, with retention of configuration at both carbons. Vinyhc halides can also be coupled with Zn—NiCl2, " " and with -BuLi in ether in the presence of MnCl2. " The coupling reaction with vinyltin reagents and vinyl halides occurs with a palladium catalyst. " ... 

Tor a coupling reaction using a butenolide-vinyltin reagent, see Rousset, S. Abarbri, M. Thibonnet, J. Duchene, A. Parrain, J.-L. Org. Lett. 1999, 1, 701. For a vinyltin reagent with a nitrogen substituent (a tinylated enamide), see Miniere, S. Cintrat, J.-C. J. Org. Chem. 2001, 66, 7385. 

Palladium-catalyzed allylic alkylation by transmetallation with Grignard reagents is less frequently encountered than with aryl- and vinyltin reagents [85]. However, a few examples are known from the literature and reported herein. In some cases, if the reactivity of such allylic-ethers or amines have been reported, the regioselectivity was not studied because of the symmetric nature of the substrates. 

Allylic halides couple effectively with vinyltin reagents to provide the corresponding 1,4-dienes in high yields.2 Like nickel- and palladium-catalyzed Grignard reactions with allylic ethers, this reaction also proceeds with net inversion of configuration at the allylic center. Similarly, vinyl epoxides react... 

Vinyltin reagents react with Z- and - 3-iodoacrylic acids in the presence of dichlorobis(acetonitrile)palladium(II) (5%) to give the corresponding dienoic acids, which have been transformed into pellitorine (1), its Z-isomer (2) and kalecide (6) [11] (Scheme 5). 

Termination occurs by transmetallation with organometallic compounds of B and Sn, followed by reductive elimination. The aryl iodide 172 underwent 5-exo cyclization. Transmetallation of the alkylpalladium with vinyltin reagent, followed by reductive elimination, afforded 173 [85]. The anion trap is not limited to the... 

Reaction of 140 with vinyltin reagent yields the cyclized product 141. The conversion can be understood by cis carbopalladation, transmetallation with the Sn reagent, and reductive elimination [45,46]. This reaction is overall cis addition to the triple bond. The intramolecular version of furan synthesis was plied to the preparation of the key intermediate of halenaquinone and halenaquinol syntheses from 142 [47]. 

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