736140-81-1Relevant articles and documents
Catalytic asymmetric epoxidation of α,β-unsaturated N-acylpyrroles as monodentate and activated ester equivalent acceptors
Matsunaga, Shigeki,Qin, Hongbo,Sugita, Mari,Okada, Shigemitsu,Kinoshita, Tomofumi,Yamagiwa, Noriyuki,Shibasaki, Masakatsu
, p. 6630 - 6639 (2007/10/03)
Catalytic asymmetric epoxidation of α,β-unsaturated N-acylpyrroles as monodentate and activated ester equivalent acceptors is described. A Sm(O-i-Pr)3/(R)-H8-BINOL complex promoted the epoxidation reaction to afford products in high yield (up to quant) and high enantiomeric excess (up to >99.5% ee). Reaction proceeded smoothly using cumene hydroperoxide (CMHP) with low explosive hazard, and completed within 0.2-0.5 h with 5 mol % catalyst. Catalyst loading was successfully reduced to as little as 0.02 mol %. The N-acylpyrrole properties as well as efficient synthesis of α,β-unsaturated N-acylpyrroles are also described.
Sequential Wittig olefination-catalytic asymmetric epoxidation with reuse of waste Ph3P(O): Application of α,β-unsaturated N-Acyl pyrroles as ester surrogates
Kinoshita, Tomofumi,Okada, Shigemitsu,Park, Sun-Ryung,Matsunaga, Shigeki,Shibasaki, Masakatsu
, p. 4680 - 4684 (2007/10/03)
Waste 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.
