One‐Pot Synthesis of 3‐Alkylidenephthalides from Benzoic Acids by a Rhodium‐Catalyzed
<i>ortho</i>
‐CH Acylation Process
作者:Grégory Danoun、Patrizia Mamone、Lukas J. Gooßen
DOI:10.1002/chem.201303426
日期:2013.12.16
CH functionalization: A [Rh(cod)Cl]2/CsF (cod=1,5‐cyclooctadiene) catalyst system was found to promote the straightforward synthesis of 3‐alkylidenephthalides from benzoicacids and aliphatic acids or anhydrides through a one‐pot CH acylation/acylalization/elimination cascade (see scheme).
The first asymmetric hydrogenation of 3‐ylidenephthalides has been developed using the IrI complex of a spiro[4,4]‐1,6‐nonadiene‐based phosphine‐oxazoline ligand (SpinPHOX) as the catalyst, affording a wide variety of chiral 3‐substituted phthalides in excellent enantiomeric excesses (up to 98 % ee). The utility of the protocol has been demonstrated in the asymmetricsynthesis of chiral drugs NBP and