In:
ChemSusChem, Wiley, Vol. 12, No. 14 ( 2019-07-19), p. 3363-3369
Abstract:
A convenient protocol for stereodivergent hydrogenation of alkynes to E ‐ and Z ‐alkenes by using nickel catalysts was developed. Simple Ni(NO 3 ) 2 ⋅6 H 2 O as a catalyst precursor formed active nanoparticles, which were effective for the semihydrogenation of several alkynes with high selectivity for the Z ‐alkene ( Z / E 〉 99:1). Upon addition of specific multidentate ligands (triphos, tetraphos), the resulting molecular catalysts were highly selective for the E ‐alkene products ( E/Z 〉 99:1). Mechanistic studies revealed that the Z ‐alkene‐selective catalyst was heterogeneous whereas the E ‐alkene‐selective catalyst was homogeneous. In the latter case, the alkyne was first hydrogenated to a Z ‐alkene, which was subsequently isomerized to the E ‐alkene. This proposal was supported by density functional theory calculations. This synthetic methodology was shown to be generally applicable in 〉 40 examples and scalable to multigram‐scale experiments.
Type of Medium:
Online Resource
ISSN:
1864-5631
,
1864-564X
DOI:
10.1002/cssc.201900784
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
2411405-4
