Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• -defined binding pockets, offer a preorganized arrangement of functional groups as a suitable microenvironment for organocatalysis. In 2008, Kohnke, Soriente and co-workers first reported [37] the H-bonding organocatalytic activity of calix[4]pyrrole derivatives 3 and 4 and acyclic dipyrromethane 5 for the

• ]pyrrole α,β-isomer 4 was found to be catalytically active providing a 57% conversion to 10, suggesting a concerted cycloaddition mechanism. Calix[4]pyrrole α,α-isomer 3 and dipyrromethane 5 were catalytically inactive. The authors concluded that the catalytic inactivity of 3 is caused by the parallel

• acetonitrile, calix[4]pyrrole enhanced its solubility, contributing to its indirect activation. Various control experiments, such as using CuI with and without calix[4]pyrrole and using dipyrromethane as another potential co-catalyst, have confirmed the role of calix[4]pyrrole as a promoter. Recently

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• for diverse applications in future studies. Keywords: condensation; co-timerization; dipyrromethane; Friedel–Crafts acylation; heterocycles; pyrrole; truxene; Introduction The scaffold of truxene (10,15‐dihydro‐5H‐diindeno[1,2‐a;1′,2′‐c]fluorene) and its congeners comprises three fluorene subunits

• outstanding optical properties [43]. Herein, we present for the first time three new mono-, di-, tri-dipyrromethane appended truxene derivatives with the intention to explore them for future sensing and/or binding properties. Results and Discussion To achieve our goal towards the construction of truxene

• some reported mono-, di- and tri-dipyrromethane derivatives [44][45][46][47][48][49]. UV–vis absorption (left) and fluorescence spectra (right) recorded in chloroform. Time-resolved fluorescence lifetime. Synthesis of the mono-DPM-based truxene derivative 14. Synthesis of di- and tri-DPM-based truxene

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• been reported involving the use of A3-bilanes [30][31] or dipyrromethane–dicarbinols [32], the modification of A4-porphyrins [33], or the reaction of pyrrole with different aldehydes [34]. In the present work, the applied synthetic method provided the A3B-porphyrins in a single-step reaction from

•  1). In our previous works, we have shown that the reaction of pyrrole with N-tosylimines leads to pyrrole sulfonamides as the main products [35]. In another work, in the synthesis of dipyrromethane structures, we have proven the formation of azafulvene intermediates by Cu(OTf)2-appended elimination

• were between 7–18%. Synthesis of tripyrrane 5 5,10-Bis(4-trifluoromethylphenyl)tripyrromethane (5) was obtained as side product of dipyrromethane synthesis by the condensation of pyrrole and 4-(trifluoromethyl)benzaldehyde. A typical procedure involves 4-(trifluoromethyl)benzaldehyde (28.7 mmol) and

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• ]. The latter incorporated two dipyrromethane/dipyrromethene units connected through iminoalkyl bridges. The architecture of the macrocycles, and their anticipated dynamic behaviour, wherein two dipyrromethene parts can come closer or further due to the flexibility of the alkyl linker, is reminiscent to

• have developed an alternative approach toward porphyrinoid-crown ether hybrids [66][67]. Replacing the tripyrrane moiety with a meso-disubstituted dipyrromethane allowed the creation of a series of macrocycles 16–19 differing in the dimensions and heteroatoms within the cavity (Figure 11). The

• synthesis of these compounds involved the condensation of a meso-disubstituted dipyrromethane with diamines incorporating the crown ether/azacrown segment in the presence of boron trifluoride diethyl etherate as a catalyst [66]. The treatment of compound 16 with potassium hydride yielded 16-K2, a suitable

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• showed good fluorescence emission; thus, it could be used as a photodynamic therapy application. In 2013, Liu and colleagues [66] used a click chemistry approach to synthesize meso-tetratriazole-bridged Zn(II) porphyrin-boron dipyrromethane conjugates 164 in 85% yield by reacting porphyrin 146 with

Synthesis of meso-pyrrole-substituted corroles by condensation of 1,9-diformyldipyrromethanes with pyrrole

• Baris Temelli and
• Pinar Kapci

Beilstein J. Org. Chem. 2022, 18, 1403–1409, doi:10.3762/bjoc.18.145

• amount of pyrrole is presented for the first time. This procedure is a simple and efficient way for the preparation of corroles with a polymerizable substituent on meso-positions. Keywords: corrole; dipyrromethane; macrocycles; metal triflates; pyrrole; Introduction Corroles, a member of contracted

• several methods including; (i) the condensation of pyrrole or dipyrromethanes with aldehydes [14][15][16], (ii) the reaction of 2,2’-bipyrrole with dipyrromethane-1,9-dicarbinols [17][18], (iii) the condensation of bipyrrole-5,5’-dicarbinols with dipyrromethanes [19], (iv) the reaction of dipyrromethane

• -1,9-dicarbinols with pyrrole [20][21], (v) the condensation of dipyrromethane-1-carbinols with dipyrromethanes [22] and (vi) the reaction of tripyrranes with aldehydes [23]. Although many different substituents can be attached to the meso-position of corroles using all these methods, to the best of

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

• Takahide Shimada,
• Shigeki Mori,
• Masatoshi Ishida and
• Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

• , Japan 10.3762/bjoc.16.53 Abstract A series of α- and β-ethynyl-substituted BODIPY derivatives (3a, 4a, 5a, 5b, 6a, 6b) were synthesized by gold(I)-catalyzed direct C–H alkynylation reactions of dipyrromethane and BODIPY, respectively, with ethynylbenziodoxolone (EBX) in a regioselective manner

• ][11][12], photocatalysis [13][14][15][16], optics [17][18][19][20], and so forth. The structure of BODIPY derivatives is composed of a dipyrromethene (an oxidized form of dipyrromethane 2) and a coordinated difluoroboron moiety [21]. The rigid π-conjugated scaffold of BODIPYs demonstrates fascinating

• prepared regioselectively, through the C–H alkynylation of 1 without any directing groups. In addition, the corresponding dipyrromethane 2, which is a precursor of BODIPY, was first transformed into the alkynylated form under catalytic conditions, and subsequent oxidation followed by boron complexation to

Synthesis and spectroscopic properties of β-meso directly linked porphyrin–corrole hybrid compounds

• Baris Temelli and
• Hilal Kalkan

Beilstein J. Org. Chem. 2018, 14, 187–193, doi:10.3762/bjoc.14.13

• , entry 20). With the optimized reaction conditions in hand, different meso-substituted dipyrromethanes 2 were subjected to the condensation reactions (Scheme 3). Electronic properties of the substituents on the dipyrromethane generally did not show significant effects on the reactions except for the

• with aldehydes [42]. When electron-withdrawing 4-nitrophenyl and pentafluorophenyl substituents were used on the dipyrromethane, hybrid compounds 4c and 4e were isolated in 16% and 20% yields, respectively. The synthesis of 4e with InCl3 afforded a very low yield, thus an equimolar amount of AlCl3 was

Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

• Anna Kuźnik,
• Roman Mazurkiewicz and
• Beata Fryczkowska

Beilstein J. Org. Chem. 2017, 13, 2710–2738, doi:10.3762/bjoc.13.269

• Gryko and Flamigni et al. for the preparation of 6-formylcoumarin derivatives 109 that are used in the synthesis of dyads 111 consisting of coumarin and corrole units (Scheme 61). The latter synthesis took place by condensation of formylcoumarins 109 with 5-(pentafluorophenyl)dipyrromethane (110) [76

Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition

• Nicolas Desbois,
• Sandrine Pacquelet,
• Adrien Dubois,
• Clément Michelin and
• Claude P. Gros

Beilstein J. Org. Chem. 2015, 11, 2202–2208, doi:10.3762/bjoc.11.239

• and alkyne derivatives to further interconnect by microwave-assisted click reaction. Azidocorroles/porphyrins Azidocorrole 1 [9] was obtained by the condensation of the corresponding meso-mesityl-substituted dipyrromethane with 4-azidobenzaldehyde in the presence of a catalytic amount of

Discrete multiporphyrin pseudorotaxane assemblies from di- and tetravalent porphyrin building blocks

• Mirko Lohse,
• Larissa K. S. von Krbek,
• Sebastian Radunz,
• Suresh Moorthy,
• Christoph A. Schalley and
• Stefan Hecht

Beilstein J. Org. Chem. 2015, 11, 748–762, doi:10.3762/bjoc.11.85

• ), BF3·Et2O, DDQ, CHCl3, rt; b) Zn(OAc)2, CHCl3/MeOH, rt; c) dipyrromethane 6, BF3·Et2O, DDQ, CHCl3, rt; d) Zn(OAc)2, CHCl3/MeOH, rt; e) 1. benzylamine, trimethyl orthoformate, rt, 2. NaBH4, THF/MeOH, rt; f) Boc2O, triethylamine, CH2Cl2, rt; g) 1. ethynyltrimethylsilane, CuI, PPh3, Pd(PPh3)4, TEA

• , 3,4-dihydroxybenzaldehyde, DMF, 85 °C; d) 1. pyrrole (4), propionic acid, 140 °C, 2. Zn(OAc)2, MeOH/CHCl3, rt; e) 1. dipyrromethane (6), BF3·Et2O, DDQ, CHCl3, rt, 2. Zn(OAC)2, MeOH/CHCl3, rt. Supporting Information Supporting Information File 370: Detailed synthetic procedures. Acknowledgements The