Highly Active Multidentate Ligand-Based Alkyne Metathesis Catalysts.
Alkyne metathesis catalysts composed of molybdenum(VI) propylidyne and multidentate tris(2-hydroxylbenzyl)methane ligands have been developed, which exhibit excellent stability (remains active in solution for months at room temperature), high activity, and broad functional-group tolerance. The homodimerization and cyclooligomerization of monopropynyl or dipropynyl substrates, including challenging heterocycle substrates (e.g., pyridine), proceed efficiently at 40-55 °C in a closed system. The ligand structure and catalytic activity relationship has been investigated, which shows that the ortho groups of the multidentate phenol ligands are critical to the stability and activity of such a catalyst system.
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
Ya
Y
Du
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
Haishen
H
Yang
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
Chengpu
C
Zhu
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
Michael
M
Ortiz
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
Kenji D
KD
Okochi
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
Richard
R
Shoemaker
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
Yinghua
Y
Jin
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA. wei.zhang@colorado.edu.
Wei
W
Zhang
alkylidyne; alkyne metathesis; homogeneous catalysis; molybdenum; multidentate ligand