24251-86-3Relevant articles and documents
Copper-catalyzed alkyl-alkyl cross-coupling reactions using hydrocarbon additives: Efficiency of catalyst and roles of additives
Iwasaki, Takanori,Imanishi, Reiko,Shimizu, Ryohei,Kuniyasu, Hitoshi,Terao, Jun,Kambe, Nobuaki
, p. 8522 - 8532 (2015/01/08)
Cross-coupling of alkyl halides with alkyl Grignard reagents proceeds with extremely high TONs of up to 1230000 using a Cu/unsaturated hydrocarbon catalytic system. Alkyl fluorides, chlorides, bromides, and tosylates are all suitable electrophiles, and a TOF as high as 31200 h-1 was attained using an alkyl iodide. Side reactions of this catalytic system, i.e., reduction, dehydrohalogenation (elimination), and the homocoupling of alkyl halides, occur in the absence of additives. It appears that the reaction involves the β-hydrogen elimination of alkylcopper intermediates, giving rise to olefins and Cu-H species, and that this process triggers both side reactions and the degradation of the Cu catalyst. The formed Cu-H promotes the reduction of alkyl halides to give alkanes and Cu-X or the generation of Cu(0), probably by disproportionation, which can oxidatively add to alkyl halides to yield olefins and, in some cases, homocoupling products. Unsaturated hydrocarbon additives such as 1,3-butadiene and phenylpropyne play important roles in achieving highly efficient cross-coupling by suppressing β-hydrogen elimination, which inhibits both the degradation of the Cu catalyst and undesirable side reactions.
Nickel-catalyzed reductive cross-coupling of aryl halides with alkyl halides
Everson, Daniel A.,Shrestha, Ruja,Weix, Daniel J.
supporting information; experimental part, p. 920 - 921 (2010/03/31)
(Chemical Equation Presented) The direct reductive cross-coupling of alkyl halides with aryl halides is described. The transformation is efficient (equimolar amounts of the starting materials are used), generally high-yielding (all but one between 55 and 88% yield), highly functional-group-tolerant [OH, NHBoc, NHCbz, Bpin, C(O)Me, CO2Et, and CN are all tolerated], and easy to perform (uses only benchtop-stable reagents, tolerates small amounts of water and oxygen, changes color when complete, and uses filtration workup). The reaction appears to avoid the formation of intermediate organomanganese species, and a synergistic effect was found when a mixture of two ligands was employed.
