在手性聚α-氨基酸催化下，缺電子烯烴在氧化劑（過氧化氫或過氧化脲）氧化下得到單一構(gòu)型的環(huán)氧化物的反應(yīng)。此反應(yīng)通常在堿性條件下進(jìn)行。
反應(yīng)機(jī)理
反應(yīng)屬于親核環(huán)氧化，底物中沒有吸電子基團(tuán)的話反應(yīng)不能進(jìn)行。
反應(yīng)實(shí)例
Catalyst (1). To a solution of N-carboxy-L-alanine anhydride (2.5 g, 21.7 mmol) in anh MeCN (50 mL) was added MeCN (20 mL with 0.43 mmol H2O). After 4 days stirring at 20 C the solvent was removed in vacuum and the residue stirred for 24 h in Et2O, filtered and dried.
Epoxide (3). To a solution of chalcone 2 (500 mg, 2.4 mmol) in PhMe (6 mL) was added 1 (400 mg) and then the mixture was stirred for 30 min at 20 C. The mixture was added to a solution of NaOH in H2O2 (0.08 g/mL, 4.4 mL) and stirred for 24 h. The reaction was monitored by TLC (silica gel, PE:Et2O 9:1). Usual workup and chromatography afforded 494 mg of 3 (92%, 96% ee).
【Julia S, Colonna S, Tetrahedron, 1984, 40, 5207】
Epoxide (5). To I-PLL(immobilized poly-L-leucine, 7 g) in THF (50 mL) were added DBU (4.1 mL, 27.48 mmol) and UHP (Urea hydrogen peroxide)
(2.07 g, 21.98 mmol). Under stirring was added 4 (4.01 g, 18.37 mmol), followed after 3 h by a second quantity of DBU and UHP. Separation of the epoxide 3.20 g of 5 (70% yield from 4), mp 53–55 C, 96% ee.
【Roberts SM, J Chem Soc Perkin 1, 1997, 3501】
相關(guān)文獻(xiàn)
1 Julia S, Colonna S Angew Chem Int 1980 19 929
2 Julia S, Colonna S J Chem Soc Perkin 1 1982 1317
3 Julia S, Colonna S Tetrahedron 1983 39 1655
4 Julia S, Colonna S Tetrahedron 1984 40 5207
5 Roberts SM J Chem Soc Perkin 1 1997 3501
6 Geller T J Chem Soc Perkin 1 1999 1397
7 Jayaprakash D J Mol Catal A Chem 2003 196 145
8 Shibasaki M Chem Asian J 2007 2 257
9 Shing TKM Tet Asymm 2009 20 883
編譯自：Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 239-240.
