Asymmetrische Katalysen, 771 Neue optisch aktive Pyrazolderivate für die enantioselektive Katalyse

Asymmetric Catalysis, 77 1 . – New Optically Active Pyrazole Derivatives for Enantioselective Catalysis Starting from the amines 3–6 and the dipyrazolopyrazinedione 2 , the optically active (pyrazolylmethyl)amines 11–14 have been synthesized. Furthermore, the preparation of the (+)‐camphor‐derived optically active pyrazole 17 is described. Pyrazoles 11–13 and 17 are introduced as chiral building blocks into the 2‐(1‐pyrazolyl)pyridines 30–33 . The optically active compounds 23–25 are formed from 2‐3(5)‐pyrazolylpyridine and 2,6‐bis3(5‐)pyrazolylpyridine, respectively, and (+)‐3‐(bromomethyl)pinane. The pyrazole derivatives 27–29 contain (+)‐(1‐phenylethyl)hydrazine as the optically active component.