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Synthesis, Structure, and Catalytic Activity of Ti IV and Zr IV Complexes Derived from ( R )‐2,2′‐Diamino‐1,1′‐binaphthyl‐Based N 4 ‐Donor Ligands
Author(s) -
Xiang Li,
Song Haibin,
Zi Guofu
Publication year - 2008
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200701105
Subject(s) - chemistry , hydroamination , catalysis , amide , zirconium , yield (engineering) , medicinal chemistry , titanium , diamine , stereochemistry , nuclear chemistry , polymer chemistry , inorganic chemistry , organic chemistry , materials science , metallurgy
Reaction of ( R )‐bis(pyrrol‐2‐ylmethyleneamino)‐1,1′‐binaphthyl ( 1 H 2 ) or ( R )‐ N , N′ ‐bis(pyridin‐2‐ylmethyl)‐1,1′‐binaphthyl‐2,2′‐diamine ( 2 H 2 ) with Zr(NMe 2 ) 4 (1 equiv.) gives chiral zirconium amides 1 ‐Zr(NMe 2 ) 2 · C 7 H 8 ( 4· C 7 H 8 ) or 2 ‐Zr(NMe 2 ) 2 ( 6 ) in good yields, respectively. Under similar conditions, 1 H 2 reacts with Ti(NMe 2 ) 4 (1 equiv.) to give chiral titanium amide 1 ‐Ti(NMe 2 ) 2 · C 6 H 6 ( 3· C 6 H 6 ), whereas treatment of 2 H 2 with Ti(NMe 2 ) 4 (1 equiv.) leads to the isolation of bis(ligated) product ( 2 ) 2 ‐Ti · C 7 H 8 ( 5· C 7 H 8 ) in 74 % yield. All complexes were characterized by various spectroscopic techniques, elemental analysis, and X‐ray diffraction analysis. Zirconium amides 4 and 6 are active catalysts for the asymmetric hydroamination/cyclization of aminoalkenes, and cyclic amines were obtained in good‐to‐excellent yields with moderate ee values (up to 59 %); titanium amides 2 and 5 were not active under the reaction conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)