Conversion of <i>F</i>‑BODIPYs to <i>Cl</i>-BODIPYs: Enhancing the Reactivity of <i>F</i>‑BODIPYs

A new method for the synthesis of <i>Cl</i>-BODIPYs from <i>F</i>-BODIPYs is reported, merely requiring treatment of the <i>F</i>-BODIPY with boron trichloride. <i>Cl</i>-BODIPYs are exploited as synthetic intermediates generated in situ for the overall conversion of <i>F</i>-BODIPYs to <i>O</i>- and <i>C</i>-BODIPYs in high overall yields using a mild one-pot procedure. This route enables <i>F</i>-BODIPYs to be transformed into derivatives that are not accessible via the direct route, as demonstrated via the use of 1,3-propanediol

Correction to One-Pot Synthesis of Asymmetric Annulated Bis(pyrrole)s

Correction to One-Pot Synthesis of Asymmetric Annulated Bis(pyrrole)

Idun (Årg. 29, N:r 50)

An asymmetric meso-<i>H</i> dipyrrin featuring a conjugated terminal alkyne substituent was converted to its corresponding difluoro boron complex, and the extent of π-conjugation was extended using Sonogashira cross-coupling. Treatment of the alkyne-substituted dipyrrin with BF₃·OEt₂ and NEt₃ revealed the reactivity of the conjugated terminal alkyne toward Lewis-activated electrophilic substitution and led to the isolation of <i>F</i>-BODIPYs bearing terminal bromovinyl and enol substituents

Use of <i>F</i>-BODIPYs as a Protection Strategy for Dipyrrins: Optimization of BF₂ Removal

We recently reported the first general method for the deprotection of 4,4-difluoro-4-bora-3a,4a-diaza-<i>s</i>-indacenes (<i>F</i>-BODIPYs) involving a microwave-assisted procedure for the removal of the BF₂ moiety, and liberation of the corresponding free-base dipyrrin. Further optimization of the reaction has resulted in a more convenient and accessible protocol. The availability of this new methodology enables BF₂-complexation to be used as a dipyrrin protection strategy. Herein lies a detailed examination of the deprotection reaction, with a view to optimization and gaining mechanistic insight, and its application in facilitating a multistep synthesis of pyrrolyldipyrrins

Use of <i>F</i>-BODIPYs as a Protection Strategy for Dipyrrins: Optimization of BF₂ Removal

We recently reported the first general method for the deprotection of 4,4-difluoro-4-bora-3a,4a-diaza-<i>s</i>-indacenes (<i>F</i>-BODIPYs) involving a microwave-assisted procedure for the removal of the BF₂ moiety, and liberation of the corresponding free-base dipyrrin. Further optimization of the reaction has resulted in a more convenient and accessible protocol. The availability of this new methodology enables BF₂-complexation to be used as a dipyrrin protection strategy. Herein lies a detailed examination of the deprotection reaction, with a view to optimization and gaining mechanistic insight, and its application in facilitating a multistep synthesis of pyrrolyldipyrrins

Synthesis and Photobiological Activity of Ru(II) Dyads Derived from Pyrrole-2-carboxylate Thionoesters

The synthesis and characterization of a series of heteroleptic ruthenium­(II) dyads derived from pyrrole-2-carboxylate thionoesters are reported. Ligands bearing a conjugated thiocarbonyl group were found to be more reactive toward Ru­(II) complexation compared to analogous all-oxygen pyrrole-2-carboxylate esters, and salient features of the resulting complexes were determined using X-ray crystallography, electronic absorption, and NMR spectroscopy. Selected complexes were evaluated for their potential in photobiological applications, whereupon all compounds demonstrated in vitro photodynamic therapy effects in HL-60 and SK-MEL-28 cells, with low nanomolar activities observed, and exhibited some of the largest photocytotoxicity indices to date (>2000). Importantly, the Ru­(II) dyads could be activated by relatively soft doses of visible (100 J cm^–2, 29 mW cm^–2) or red light (100 J cm^–2, 34 mW cm^–2), which is compatible with therapeutic applications. Some compounds even demonstrated up to five-fold selectivity for malignant cells over noncancerous cells. These complexes were also shown to photocleave, and in some cases unwind, DNA in cell-free experiments. Thus, this new class of Ru­(II) dyads has the capacity to interact with and damage biological macromolecules in the cell, making them attractive agents for photodynamic therapy

An Improved Method for the Synthesis of <i>F</i>-BODIPYs from Dipyrrins and Bis(dipyrrin)s

An improved methodology for the synthesis of <i>F-</i>BODIPYs from dipyrrins and bis(dipyrrin)s is reported. This strategy employs lithium salts of dipyrrins as intermediates that are then treated with only 1 equiv of boron trifluoride diethyletherate to obtain the corresponding <i>F-</i>BODIPYs. This scalable route to <i>F</i>-BODIPYs renders high yields with a facile purification process involving merely filtration of the reaction mixture through Celite in many cases

An Improved Method for the Synthesis of <i>F</i>-BODIPYs from Dipyrrins and Bis(dipyrrin)s

An improved methodology for the synthesis of <i>F-</i>BODIPYs from dipyrrins and bis(dipyrrin)s is reported. This strategy employs lithium salts of dipyrrins as intermediates that are then treated with only 1 equiv of boron trifluoride diethyletherate to obtain the corresponding <i>F-</i>BODIPYs. This scalable route to <i>F</i>-BODIPYs renders high yields with a facile purification process involving merely filtration of the reaction mixture through Celite in many cases

An Improved Method for the Synthesis of <i>F</i>-BODIPYs from Dipyrrins and Bis(dipyrrin)s

An improved methodology for the synthesis of <i>F-</i>BODIPYs from dipyrrins and bis(dipyrrin)s is reported. This strategy employs lithium salts of dipyrrins as intermediates that are then treated with only 1 equiv of boron trifluoride diethyletherate to obtain the corresponding <i>F-</i>BODIPYs. This scalable route to <i>F</i>-BODIPYs renders high yields with a facile purification process involving merely filtration of the reaction mixture through Celite in many cases

Eight-Membered Ring-Containing Jadomycins: Implications for Non-enzymatic Natural Products Biosynthesis

Jadomycin Oct (<b>1</b>) was isolated from Streptomyces venezuelae ISP5230 and characterized as a structurally unique eight-membered l-ornithine ring-containing jadomycin. The structure was elucidated through the semisynthetic derivatization of starting material via chemoselective acylation of the l-ornithine α-amino group using activated succinimidyl esters. Incorporation of 5-aminovaleric acid led to jadomycin AVA, a second eight-membered ring-containing jadomycin. These natural products illustrate the structural diversity permissible from a non-enzymatic step within a biosynthetic pathway and exemplifies the potential for discovery of novel scaffolds