Templated synthesis of a large and flexible covalent porphyrinic cage bearing orthogonal recognition sites

Abstract

A large covalent cage incorporating two porphyrins attached by four long and flexible polyether chains each bearing two 3-pyridyl ligands was synthesized from a DABCO-templated olefin metathesis reaction. The X-ray structure of the cage with the DABCO coordinated inside the cavity to the two zinc(II) porphyrins reveals a highly symmetric structure.

Positive Allosteric Control of Guests Encapsulation by Metal Binding to Covalent Porphyrin Cages

“…Our previous work has focused on the synthesis of coordination and covalent architectures incorporating metalloporphyrins . In particular, flexible covalent cages incorporating orthogonal binding sites, metalloporphyrins and 1,2,3‐triazoles, were obtained using a DABCO‐templated copper(I)‐catalyzed alkyne‐azide reaction (DABCO=1,4‐diazabicyclo[2.2.2]octane).…”

“…[11,[59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75] Our previous work has focused on the synthesis of coordination [76] andc ovalent architectures incorporating metalloporphyrins. [77][78][79] In particular,f lexible covalent cages incorporating orthogonal binding sites, metalloporphyrins and 1,2,3-triazoles, were obtained using aD ABCO-templated copper(I)-catalyzed alkyne-azider eaction (DABCO = 1,4-diazabicyclo[2.2.2]octane). This templated synthesise nabledt op erform simultaneously the macrocyclization reaction and the synthesis of four out of eight triazole ligands of the structure,t herefore, limiting the synthetic effort to obtain these molecules.…”

Tautomerism and Atropisomerism in Free‐Base (meso)‐Strapped Porphyrins: Static and Dynamic Aspects

“…Besides their exceptional optical, photophysical and electrochemical properties extensively exploited for decades in donor-acceptor systems [1] and molecular photovoltaics, [2][3][4] porphyrins (Pors) have also proved to be extraordinary supramolecular scaffolds in the design of sophisticated 1D-, 2D-and 3D-dimensional architectures, [5][6][7][8][9] covalently or self-assembled, [10][11][12][13][14] including chiral materials [15][16][17] or sensors, [18] molecular cages, [19][20][21][22][23] turnstiles, [24] tweezers [25,26] and dendrimer cores. [9] Since the first reported example in 1969, [27] atropisomerism in porphyrins has been a concept widely exploited in these kinds of architectures (and, in particular, in tetra-meso-arylporphyrins).…”

Control of the cavity size of flexible covalent cages by silver coordination to the peripheral binding sites

“…With the aim of building multicomponent flexible porphyrin containers with orthogonal binding sites, we have reported the synthesis of porphyrinic covalent cages with eight 3--pyridyl ligands thanks to a DABCO--templated ring--closing metathesis reaction (DABCO: 1,4-diazabicyclo[2.2.2]octane). 8 Based on these results, it was envisioned to use the distal coordination sites incorporated in flexible porphyrin containers to adjust their cavity size.…”