Sequential Wittig Olefination–Catalytic Asymmetric Epoxidation with Reuse of Waste Ph 3 P(O): Application of α,β‐Unsaturated N ‐Acyl Pyrroles as Ester Surrogates
2003; Wiley; Volume: 42; Issue: 38 Linguagem: Inglês
10.1002/anie.200352509
ISSN1521-3773
AutoresTomofumi Kinoshita, Shigemitsu Okada, Sun‐Ryung Park, Shigeki Matsunaga, Masakatsu Shibasaki,
Tópico(s)Chemical Synthesis and Reactions
ResumoWaste not, want not: Efficient one-pot access to optically active epoxides with 96 to 99.5 % ee from a variety of aldehydes is described. In a sequential process, the Ph3P(O) by-product of a Wittig reaction acts as a modulator for the samarium catalyst in the asymmetric epoxidation of the conjugated N-acyl pyrrole Wittig product (see scheme). The N-acyl pyrrole functionality is key to the high reactivity and selectivity observed. R=alkyl, aryl, vinyl.
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