Design and Synthesis of the First Spiro Bis(isoxazoline) Derivatives as Asymmetric Ligands
摘要:
[GRAPHICS]A chiral bis(isoxazoline) ligand (SPRIX) containing a rigid spiro skeleton was designed and synthesized via a double intramolecular nitrile oxide cycloaddition, The optically pure SPRIX greatly accelerated the Cu(acac)(2)-catalyzed asymmetric reaction of diisopropylzinc with cyclohexenone to give the Michael adduct with 49% ee. This is the first example of the use of an isoxazoline ligand for a transition metal catalyzed reaction. The X-ray crystallographic analysis of the hexacoordinated copper complex of SPRIX confirmed the ligand character.
Spirocycle assembly through selective tandem ring closing metathesis reactions
摘要:
A range of functionalised spirocyclic systems have been prepared under mild and neutral conditions by tandem selective ring closing olefin metathesis reactions. Additionally, a marked preference for 5-membered ring closure over 7-membered ring closure was observed which appears to be a result of a kinetically favoured cyclisation process. (C) 1999 Elsevier Science Ltd. All rights reserved.
Spirocycle assembly through selective tandem ring closing metathesis reactions
作者:Martin J. Bassindale、Peter Hamley、Andreas Leitner、Joseph P.A. Harrity
DOI:10.1016/s0040-4039(99)00375-5
日期:1999.4
A range of functionalised spirocyclic systems have been prepared under mild and neutral conditions by tandem selective ring closing olefin metathesis reactions. Additionally, a marked preference for 5-membered ring closure over 7-membered ring closure was observed which appears to be a result of a kinetically favoured cyclisation process. (C) 1999 Elsevier Science Ltd. All rights reserved.
Design and Synthesis of the First Spiro Bis(isoxazoline) Derivatives as Asymmetric Ligands
作者:Midori A. Arai、Takayoshi Arai、Hiroaki Sasai
DOI:10.1021/ol9902881
日期:1999.12.1
[GRAPHICS]A chiral bis(isoxazoline) ligand (SPRIX) containing a rigid spiro skeleton was designed and synthesized via a double intramolecular nitrile oxide cycloaddition, The optically pure SPRIX greatly accelerated the Cu(acac)(2)-catalyzed asymmetric reaction of diisopropylzinc with cyclohexenone to give the Michael adduct with 49% ee. This is the first example of the use of an isoxazoline ligand for a transition metal catalyzed reaction. The X-ray crystallographic analysis of the hexacoordinated copper complex of SPRIX confirmed the ligand character.