TY - JOUR
T1 - In situ enzymatic screening (ISES) of P,N-ligands for Ni(0)-mediated asymmetric intramolecular allylic amination
AU - Berkowitz, David B.
AU - Shen, Weijun
AU - Maiti, Gourhari
N1 - Funding Information:
The authors thank the NSF (CHE-0317083) for support. D.B.B. acknowledges the Alfred P. Sloan Foundation for a fellowship. This research was facilitated by shared instrumentation grants for NMR (NIH SIG-1-510-RR-06301, NSF CHE-0091975, NSF MRI-0079750) and GC/MS (NSF CHE-9300831), respectively.
PY - 2004/9/20
Y1 - 2004/9/20
N2 - An in situ enzymatic screening (ISES) approach to rapid catalyst evaluation recently pointed to Ni(0) as a new candidate transition metal for intramolecular allylic amination. This led to further exploration of chiral bidentate phosphine ligands for such transformations. Herein, a variety of P,N-ligands are examined for this Ni(0)-chemistry, using a model reaction leading into the vinylglycinol scaffold. On the one hand, an N,N-bis(2-diphenylphosphinoethyl)alkylamine ('PNP') ligand proved to be the fastest ligand yet seen for this Ni(0)-transformation. On the other, phosphinooxazoline (PHOX) ligands of the Pfaltz-Helmchen-Williams variety gave the highest enantioselectivities (up to 51% ee) among P,N-ligands examined.
AB - An in situ enzymatic screening (ISES) approach to rapid catalyst evaluation recently pointed to Ni(0) as a new candidate transition metal for intramolecular allylic amination. This led to further exploration of chiral bidentate phosphine ligands for such transformations. Herein, a variety of P,N-ligands are examined for this Ni(0)-chemistry, using a model reaction leading into the vinylglycinol scaffold. On the one hand, an N,N-bis(2-diphenylphosphinoethyl)alkylamine ('PNP') ligand proved to be the fastest ligand yet seen for this Ni(0)-transformation. On the other, phosphinooxazoline (PHOX) ligands of the Pfaltz-Helmchen-Williams variety gave the highest enantioselectivities (up to 51% ee) among P,N-ligands examined.
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U2 - 10.1016/j.tetasy.2004.06.052
DO - 10.1016/j.tetasy.2004.06.052
M3 - Article
C2 - 30147246
AN - SCOPUS:4644299776
SN - 0957-4166
VL - 15
SP - 2845
EP - 2851
JO - Tetrahedron Asymmetry
JF - Tetrahedron Asymmetry
IS - 18
ER -