Donor–Acceptor‐Substituted Phenylacetylene Macrocycles with Threefold Symmetry

Abstract

Abstract A stepwise synthesis of the donor–acceptor‐substituted macrocycle 5,21,37‐tris(diethylamino)‐13,29,45‐trinitro[2.2.2.2.2.2]metacyclophane‐1,9,17,25,33,42‐hexayne ( 1a ) from 3,5‐bis(3‐iodo‐5‐nitrophenylethynyl)‐ N , N ‐diethylaniline ( 11 ) and 3,5‐bis([3‐diethylamino‐5‐ethynylphenyl]ethynyl)nitrobenzene ( 12 ) failed, mostly due to the low solubility of 1a . The synthesis of the 5,21,37‐tris( N , N‐ di‐ n ‐hexylamino) congener of 1a , 1b , was achieved in a one‐pot reaction from 1,3‐diiodo‐5‐nitrobenzene ( 3 ) and 3,5‐diethynyl‐ N , N ‐di( n ‐hexyl)aniline ( 16 ) in 23 % yield. X‐ray investigations on 1b revealed a planar π ring system with an inner diameter of 10 Å. Despite a high absorbance of 1b at 300 nm, no measurable NLO activity was found. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)