A Highly Reactive Titanium Precatalyst for Intramolecular Hydroamination Reactions
作者:Lutz Ackermann、Robert G. Bergman
DOI:10.1021/ol0256724
日期:2002.5.1
[GRAPHIC]Tetrakisamido titanium complexes are significantly more active than Cp2TiMe2 (1) in the intramolecular hydroamination of aminoalkynes and aminoallenes. In the latter case, the regioselectivity of the transformation depends on the nature of the precatalyst, yielding the most selective and reactive catalysis with the bis(sulfonamido) complex 11.
Use of Group 4 Bis(sulfonamido) Complexes in the Intramolecular Hydroamination of Alkynes and Allenes
作者:Lutz Ackermann、Robert G. Bergman、Rebecca N. Loy
DOI:10.1021/ja0361547
日期:2003.10.1
the intramolecularhydroamination of alkynes and allenes more efficiently than Cp-based species. We report here that electron-withdrawing and sterically demanding bis(sulfonamido) ligands lead to enhanced catalytic activity. Zirconium analogues have also been prepared, and the tosyl-substituted complex 20 has been structurally characterized. As in the titanium series, bis(sulfonamido) zirconium catalysts