Heterocycles

Synthesis of 1', 2', 3', 4', 5'-Pentamethyl-3, 4-diphenylazaferrocene and Its Enantioselective C-2 Functionalization via (-)-Sparteine-Mediated Lithiation

T Fukuda, Y Koga, M Iwao

文献索引：Fukuda, Tsutomu; Koga, Yasuyuki; Iwao, Masatomo Heterocycles, 2008 , vol. 76, # 2 p. 1237 - 1248

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被引用次数: 8

摘要

Lithiation of 1', 2', 3', 4', 5'-pentamethyl-3, 4-diphenylazaferrocene (9) with sec-BuLi/(-)- sparteine (2) in Et2O at-78° C followed by quenching with electrophiles gave the C-2 functionalized azaferrocenes (17) in good enantioselectivities (up to 79% ee). In contrast, treatment of 9 with tert-BuLi/(-)-sparteine (2) leaded to lateral lithiation at the methyl group of cyclopentadienyl ring.