Resorcinarene synthesis

Sliwa W, Kozlowski C. Calixarenes and resorcinarenes synthesis, properties, and applications. Weinheim Wiley-VCH Verlag GmbH Co 2009. pp. 316. 

Sliwa, W. Kozlowski, C. (Eds) Calixarenes and Resorcinarenes. Synthesis, Properties and Applications. Wiley-VCH Weinheim, Germany, 2009. 

Resorcinarenes (see the companion chapter by Bruno Botta) date back nearly 150 years when Baeyer discovered that the mixing of aldehydes with resorcinol in the presence of strong acid produced a red resin [2]. Over a decade later, Michael successfully determined the correct chemical composition of the product, but proposed the incorrect structure [3]. The correct structure of resorcin[4]arene (1, Scheme 9.1) was first proposed by Niederl [4], but it was almost 100 years after Baeyer s initial work that Erdtman and Hogberg obtained a definitive structure [5]. Twelve years after that, Hogberg fully documented resorcinarene synthesis,... 

Molecular cavities have been intensively studied over the last decades by supramolecular chemists, since they can be used for molecular recognition, catalysis, or transport processes across membranes. Bowl-shaped molecules such as calixarenes (28), res-orcinarenes (29), or cyclotriveratrylene (CTV, 30) derivatives constitute useful building blocks for cavities since their shapes and sizes can be controlled by covalent synthesis to a remarkable degree (Figure 3.15). The inherent flexibility of calixarenes and resorcinarenes can be limited either by substitution or by bridging, respectively. 

This synthetic approach has been applied for the synthesis of cavitand 31b from the corresponding CH2CH2Ph-footed resorcinarene.)... 

Figure 2.2 Solvent free synthesis of calix[4]resorcinarene.

PPG 425 has been used in the preparation of a range of benzaldehydes that were subsequently used in the solvent free synthesis of calix[4]resorcinarenes. The aldehydes are isolated in near quantitative yields by distillation from the PPG, which can be recycled. PPG has also been used in the indium metal mediated allylation of imines and sulfonylimines. Ultrasound was used for two reasons to clean the metal surface and to increase the solubility of the imine in PPG. The solvent was recycled three times, but a desire to develop an easier drying and recycling method was indicated. 

Bismuth compounds in organic synthesis. Synthesis of resorcinarenes using bismuth triflate, K. E. Peterson, R. C. Smith and R. S. Mohan, Tetrahedron Lett., 2003,44,7723. 

Resorcinarenes are synthesized by condensation of resorcine and aldehydes.The structures of calix- and resorcinarenes are similar, the compounds differing only with respect to the number and position of substituents [51]. Since formaldehyde can be replaced by other aldehydes, the bridging methylene groups can be modified in the condensation reaction (Fig. 10.4) [52].This approach may be suitable for the parallel synthesis of more diverse recognition sites. 

Examples of Co(II) and Fe(ll) resorcinarene-based cages 7 came from the group of Harrison (Fig. 3). These are water-soluble and formed by combining C0CI2 or FeCE in aqueous solution at pH >5 with the cavitand, functionalized with four iminodiacetic acid moieties. Upon synthesis, six water molecules initially occupy the... 

Calix[4]resorcinarenes, a subclass of calixarenes, are large cyclic tetramers that have found applications as macrocyclic receptors, host molecules, host-guest complexes, and so on (Botta et al, 2005 Martinez et al., 2000 Leyton et al., 2005 Yonetake et al, 2001). It shonld be noted that the synthesis of calix[4]resorcinarenes was first reported in the late nineteenth century by Bayer based on the concentrated sulfuric acid-catalyzed cyclocondensation of benzaldehyde and resorcinol (Bayer, 1872). These cyclic compounds were synthesized by TSA (Scheme 3.8) (Karami etal.,2012f). 

Arnott G, Hunter R, Su H. Synthesis and characterization of chiral, bridged resorcinarenes as templates for asymmetric catalysis. Tetrahedron 2006 62(5) 977-91. 

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