2006

Cyclopentane derivativesQ 0030 Ligand-Induced Acceleration of the Intramolecular [3 + 2] Cycloaddition

Between Alkynes and Alkylidenecyclopropanes. — Compared to P(O-iPr)3, thereaction rate of (I) in the presence of SBP is substantially increased affording (II) in excellent yield but very poor e.e. Furthe investigations reveal the bulky phosphite PTB to be the most efficient ligand. Its use allows the preparation of the target products (IV) and (VI) with low catalyst loading. — (DURAN, J.; GULIAS, M.; CASTEDO, L.; MASCARENAS*, J. L.; Org. Lett. 7 (2005) 25, 5693-5696; Dep. Quim. Org., Fac. Quim., Univ. Santiago de Compostela, E-15782 Santiago de Compostela, Spain; Eng.) — R. Steudel

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