Robust synthesis of F-BODIPYs

Abstract

A protocol is established for the high-yielding synthesis of F-BODIPYs involving non-anhydrous reagents and not requiring precautions to exclude moisture. This simple and robust strategy simply requires a second addition of NEt and BF·OEt, midway through the reaction period. The ratio and amounts of NEt and BF·OEt used in each aliquot are critical to success (6 : 9 for each aliquot). The protocol can be completed using bench-dry apparatus, without need to achieve and maintain anhydrous conditions or solvents.

Green-Light-Sensitive BODIPY Photoprotecting Groups for Amines

“…The synthesis started with the preparation of BODIPY ester 1 in 47% yield, using an adapted procedure, based on experimental results described in the literature. , Subsequent hydrolysis of the ester and reaction with 4-nitrophenyl chloroformate yielded carbonate 3 in 59% overall yield. In our hands, this reaction proved to be scalable up to 0.5 g. In the next step, we attempted halogenation of carbonate 3 .…”

“…(5,5-Difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2′,1′f ][1,3,2]diazabo-rinin-10-yl)methyl Acetate (1) (According to Combined Literature Procedures 38,40 ). 2-Chloro-2-oxoethyl acetate (0.60 mL, 5.6 mmol, 1.2 equiv) was added to a solution of 2,4dimethylpyrrole (1.0 mL, 9.3 mmol, 2.0 equiv) in dry DCM (40 mL) under a nitrogen atmosphere.…”

Green-light photocleavable meso-methyl BODIPY building blocks for macromolecular chemistry

“…For the preparation of photoresponsive macromolecular systems based on boron dipyrromethene (BODIPY), we designed a readily accessible, modifiable and stable BODIPY platform. For this reason, compound 1 was chosen because it is relatively easily synthetically accessible [35][36][37] , offers multiple options for modification of the framework 1,38 and enables the release of caged compounds upon irradiation with green-light [23][24][25] . After the reported synthesis of the BODIPY Please do not adjust margins Please do not adjust margins framework 1, hydrolysis of the ester in the meso-position resulted the common precursor 2, which could be used for subsequent synthesis of both the AA-type bifunctional and ABtype heterobifunctional BODIPY monomers, as summarised in Scheme 1.…”

“…All BODIPY-compounds were stored in the absence of light at room temperature. Synthetic procedures 8-Acetoxymethyl-2,6-diethyl-1,3,5,7-tetramethyl pyrromethene fluoroborate, BODIPY, 1: The reaction was adapted from literature procedures [35][36][37] and carried out under argon atmosphere in the dark. To 1.0 ml 3-ethyl-2,4-dimethyl-pyrrole (7.1 mmol, 2.2 eq.)…”

Flexible BODIPY Platform That Offers an Unexpected Regioselective Heterocyclization Reaction toward Preparation of 2-Pyridone[a]-Fused BODIPYs

“…The initial rationale for using tetramethyl-containing BODIPY 1 was to explore and compare the reactivity of the methyl groups at the 1,7- versus 3,5-positions. Although 1,3,5,7-tetramethyl-2,6-dicarbethoxy-BODIPY 1 has been known since 1968, to our surprise, this platform was mentioned only in four publications to date. − Moreover, while the chemical transformations of the diphenyl-analogue V are quite well-explored, only a single paper on BODIPY 1 discussed direct nitromethylation of its meso -position and thus the reactivity of the four methyl groups in 1 remains completely unexplored . This is even more surprising taking into consideration commercial availability and ease of preparation of the 2,4-dimethyl-3-carbethoxypyrrole, which is a key precursor for synthesis of BODIPY 1 .…”