Synthesis, Characterization, and Reactivity of Arylpalladium Cyanoalkyl Complexes: Selection of Catalysts for the α-Arylation of Nitriles
作者:Darcy A. Culkin、John F. Hartwig
DOI:10.1021/ja026584h
日期:2002.8.1
reactivity of arylpalladium cyanoalkyl complexes. Complexes of 1,2-bis(diphenylphosphino)benzene (DPPBz), 1,1‘-bis(di-i-propylphosphino)ferrocene (DiPrPF), racemic-2,2‘-bis(diphenylphosphino)-1,1‘-binaphthyl (BINAP), and diphenylethylphosphine (PPh2Et) were prepared. Coordination to palladium through the α-carbon was observed for DPPBz-ligated complexes and for complexes of primary and benzylic nitrile anions
Exploring Chromium(III)−Alkyl Bond Homolysis with CpCr[(ArNCMe)<sub>2</sub>CH](R) Complexes
作者:K. Cory MacLeod、Julia L. Conway、Brian O. Patrick、Kevin M. Smith
DOI:10.1021/ja1083392
日期:2010.12.8
necessitated the use of halide-free MgR2 reagents and the Cr(III) tosylate or triflate derivatives. Alternative synthetic routes to Cr(III)-R species using the previously reported Cr(II) compounds CpCr[(ArNCMe)2CH] and sources of R· radicals (e.g., BEt3 and air) were also explored. The UV-vis spectra of the CpCr[(ArNCMe)2CH](R) complexes possessed two strong bands with maximum absorbances in the ranges
Additions of anionic nucleophiles to carbonyl compounds: Cation and e-lectrophile nature influence on ionic association vs carbonyl complexation control
作者:A. Loupy、M.C. Roux-Schmitt、J. Seyden-Penne
DOI:10.1016/s0040-4039(01)90411-3
日期:1981.1
the reaction of benzaldehyde mth LiCH2CN in THF is controlled by carbonyl complexation while uith KCH2CN the reaction is controlled by ionicassociation. In the reaction of m.Cl.C6H4CHCN−Li+ with substituted benzaldehydes carbonyl complexation prevails with p.CH3OC6H4CHO while ionicassociation dominates uith PhCHO and p.CNC6H4CHO.
Carbon−Carbon Bond-Forming Reductive Elimination from Arylpalladium Complexes Containing Functionalized Alkyl Groups. Influence of Ligand Steric and Electronic Properties on Structure, Stability, and Reactivity
作者:Darcy A. Culkin、John F. Hartwig
DOI:10.1021/om049726k
日期:2004.7.1
of the enolate or cyanoalkyl group, and complexes with more substitution at the α-carbon were less stable. Arylpalladium methyl, benzyl, enolate, cyanoalkyl, and trifluoroethyl complexes underwent carbon−carbon bond-forming reductiveelimination upon heating. Reductiveelimination was faster from complexes with electron-withdrawing substituents on the palladium-bound aryl group and with sterically hindered
一系列具有式[(DPPBz)Pd(Ar)(R)]的芳基钯烷基络合物(DPPBz = 1,2-双(二苯基膦基)苯; R =甲基,苄基,烯醇盐,氰基烷基,三氟烷基或丙二酸酯)具有我们准备揭示空间和电子参数对结构,稳定性和反应性的影响。由EtPh 2 P,1,1'-双(二异丙基膦基)二茂铁(D i(PrPF)和BINAP制备以评估辅助配体的作用。烯醇盐和氰基烷基络合物的配位模式通过光谱法结合X射线晶体学测定。在没有空间位阻的情况下,如果烯醇盐或氰基烷基反式为膦,则电子键合C键异构体;如果烯醇酸酯反式为芳基,则为O键异构体。烯醇盐和氰基烷基络合物的热力学稳定性受烯醇盐或氰基烷基的空间性质控制,并且在α-碳上具有更多取代的络合物较不稳定。芳基钯甲基,苄基,烯醇盐,氰基烷基和三氟乙基络合物在加热时进行碳-碳键形成还原性消除。从在钯结合的芳基上具有吸电子取代基和在空间上受阻的烷基上形成配合物,还原消除速