Construction of C(sp3)—C(sp3) bonds through direct nickel-catalyzed reductive cross-coupling of two structurally similar alkyl halides remains a challenge in organic synthesis. In the previous studies, under catalytic Ni(cod)2 in the presence of stoichiometric amount of Zn as reductant, two different alkyl halides can efficiently undergo coupling to give desired alkyl-alkyl products. However, one of the reactants has to be largely excessive. In order to improve coupling efficiency, this reaction by using 1 mol of (4-CI)-H-Pybox and 2 mol of Ni(cod)2 as model reactants was optimized. After screening a variety of tridentate and bidentate ligands, it was determined that the ligand remained optimal. However, bidentate ligand also gave moderate results in the presence of pyridine. This result may become important in future optimization.
XU Hai-liang1, ZHANG Yu-wei2, WANG Shu-lin1, LIANG Shuo1, TONG Wei-qi1
. Optimization of Ligands in Nickel-Catalyzed Cross-Coupling of Alkyl Halides[J]. Journal of Shanghai University, 2014
, 20(2)
: 221
-227
.
DOI: 10.3969/j.issn.1007-2861.2013.07.006
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