Several room-temperature ionic liquids (ILs) based on 1-butylimidazolium salts with varying anions were synthesized and evaluated for the preparation of biologically active substituted quinolines and fused polycyclic quinolines using the Friedlander heteroannulation reaction. On screening, 1-butylimidazolium tetrafluoroborate [Hbim]BF4 was found to be the best ionic liquid for the heteroannulation reaction, and the reasons to this effect are well explained. The reactions proceed very well under relatively mild conditions without any added catalyst. The IL acts as a promoter for this regiospecific synthesis and can be recycled. By this green approach, various quinolines were prepared in excellent yields and purity and well-characterized.

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The total synthesis of (-)-apicularen A (1), a highly cytostatic 12-membered macrolide, and its analogues is described. The convergent and distinct approach not only provides 1, but also opens the opportunity to synthesize C10-C11 functional analogues of 1. The key steps of the total synthesis include assembling of iodoalkene 12 and aldehyde 13by Nozaki-Hiyama-Kishi (NHK) coupling, stereospecific construction of 2,6-trans-disubstituted dihydropyran by Pd(II)-catalyzed 1,3-chirality transfer reaction, and Yamaguchi macrolactonization. The (17E,20Z,22Z)-heptadienoylenamine moiety in the side chain is installed by an efficient Cu(I)-mediated coupling to complete the synthesis. Analogues of C11-epi-, C11-deoxy-C10-α-hydroxy-, and C10-C11 dehydrated apicularen A 3-5 were also prepared. Cytostatic activities of (-)-apicularen A and the three analogues for three different cancer cell lines are described.

The cyclization of o-amino-substituted aromatic ketones (I) with various cyclic and acyclic ketones is readily promoted by ionic liquids to furnish quinoline derivatives (III), (V), (VII) and (IX) in high yields under mild reaction conditions. The reactivity of the ionic liquid is correlated to the basicity of its anion and the best results are obtained with [Hbim]BF 4 . -(PALIMKAR, S. S.; SIDDIQUI, S. A.; DANIEL, T.; LAHOTI, R. J.; SRINIVASAN*, K. V.; J. Org. Chem. 68 (2003) 24, 9371-9378; Div. Org. Chem., Natl. Chem. Lab., Pune 411 008, India; Eng.) -Mischke 14-159

A convergent total synthesis of (-)-apicularen A, a highly cytostatic 12-membered macrolide, has been accomplished. The key steps include assembling of iodoalkene 8 and aldehyde 9 by Nozaki-Hiyama-Kishi (NHK) coupling, stereospecific construction of 2,6-trans-disubstituted dihydropyran by Pd(II)-catalyzed 1,3-chirality transfer reaction, and Yamaguchi macrolactonization. Introduction of the (2Z,4Z)-heptadienamide moiety in the side chain by an efficient Cu(I)-mediated coupling completed the total synthesis.

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