One-pot tandem cyclization of enantiopure asymmetric cis-2,5-disubstituted pyrrolidines: Facile access to chiral 10-heteroazatriquinanes

• Ping-An Wang,
• Sheng-Yong Zhang and
• Henri B. Kagan

Beilstein J. Org. Chem. 2013, 9, 265–269, doi:10.3762/bjoc.9.32

• configurations of these new chiral 10-heteroazatriquinanes are confirmed by X-ray single-crystal diffraction analysis. Keywords: cis-2,5-disubstituted pyrrolidine; 10-heteroazatriquinane; tandem cyclization; X-ray single-crystal diffraction analysis; Introduction The azatriquinane derivatives are an important

• , this 10-heteroazatriquinane 7b possesses a rigid bowl-like molecular scaffold with a quaternary nitrogen site (N2) at the bottom of the cavity. Recently, Denmark and colleagues [25][26] have synthesized a series of chiral phase-transfer catalysts (chiral PTCs) based on a 2-azatriquinane skeleton

• ][13][14] from compounds 4 through three steps, including reduction, debenzylation and cyclization (Scheme 1), but this failed. However, we have found a novel one-pot tandem cyclization of these enantiopure asymmetric cis-2,5-disubstituted pyrrolidines to produce chiral trisubstituted 10