Tetrahedron
Synthesis of nano-scale shape-persistent macrocycles via hydrogen
bonding-promoted formation of amide and hydrazone bonds
,
a
Yuan-Yuan Chen a, Lu Wang b, Liang Zhang a, Jiang Zhu c , Hui Wang ,
*
,
a,
*
Dan-Wei Zhang a , Zhan-Ting Li
*
a Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China
b Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China
c School of Basic Medical Science, North Sichuan Medical College, Nanchong 637007, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 30 April 2014
Received in revised form 20 June 2014
Accepted 26 June 2014
Available online 30 June 2014
This paper describes the synthesis of two series of rigid macrocycles from hydrogen bonding-induced
folded aryl amide and hydrazone oligomers that bear two amines or one amine and one aldehyde.
The diamines reacted with diacyl chloride to produce amide macrocycles, whereas the latter underwent
self-coupling reactions to afford imine macrocycles. DFT calculations revealed that the new macrocycles
possess rigid planar conformations and their cavity diameters were estimated to be 1.86 nme2.75 nm.
Ó 2014 Elsevier Ltd. All rights reserved.
Keywords:
Macrocycles
Aromatic amide
Aromatic hydrazone
Hydrogen bonding
Preorganization
1. Introduction
desirable for the development of new efficient approaches for
obtaining giant aromatic macrocycles.
Pioneering works by Pedersen, Cram, and Lehn had triggered
continued research on the synthesis of macrocyclic compounds and
their discrete properties.1,2 In particular rigid macrocycles have
received considerable interest due to their predictable cavity and
high co-planarity, which facilitate applications in molecular rec-
ognition and self-assembly.3e16 In the past decade, the pre-
organization of precursors driven by continual intramolecular
hydrogen bonds has been established as a useful strategy for the
construction of aromatic amide, hydrazine, and urea macro-
cycles.13e21 Many of the macrocycles have been revealed to com-
plex molecular or ionic guests of matching size and binding sites or
stack into well-defined supramolecular aggregates.20,21 However,
most of the reported macrocycles of this family have a small cavity.
Examples of giant shape-persistent aromatic amide macrocycles
with nano-scale cavity are relatively limited.17d Given the fact that
shape-persistent giant aromatic macrocycles exhibit unique rec-
ognition, stacking, and photophysical properties,22 it is still
We previously reported the one-pot synthesis of 4-mer and 6-
mer macrocycles from monomeric diamine and diacyl chloride
precursors.20c The yields were generally good to high due to the
existence of continuous intramolecular hydrogen bonds, which
induced the last intermediate to fold for macrocyclization, as ob-
served for other related amide macrocycles.20 We also demon-
strated that, via the formation of imine or hydrazone bonds under
thermodynamic control,23 many 6-mer macrocyclic and capsular
architectures could be prepared in high to quantitative yields.16,21
We herein describe that, by rational design of precursors, two
new series of shape-persistent giant macrocycles, that is,12-mer 1a,
16-mer 1b, 9-mer 2a, and 12-mer 2b (Fig. 1), can be prepared
through the formation of amide or imine bonds from hydrogen
bonded preorganized aromatic or hydrazide segments.
2. Results and discussion
2.1. Synthesis of macrocyles 1a and 1b
Diamines 3 and 4 (Fig. 2) were first prepared for the con-
struction of new macrocycles by coupling with diacids. The two
compounds were introduced with four and two sets of three-
* Corresponding authors. Tel.: þ86 21 65643576; fax: þ86 21 65641740; e-mail
0040-4020/Ó 2014 Elsevier Ltd. All rights reserved.