Palladium catalysed coupling of the 2-iodoBODIPY 3 with a range of anilines and a primary alkylamine succeeds in generating the corresponding 2-aminoBODIPYs. These 2-aminoBODIPY derivatives are non-emissive and quantum chemical calculations and electrochemistry are consistent with charge transfer from the amine substituent. Attenuation of this charge transfer pathway by conversion of the 1,2-phenylenediamine derivative 9 into the corresponding benzimidazolone 10 restores the fluorescence and has been used as the basis for a fluorescence sensor for phosgene.

A homologous series of triaryl-like KITPHOS-type monophosphines containing one, two, or three bulky 12-phenyl-9,10-dihydro-9,10-ethenoanthracene (KITPHOS) units have been developed, and the influence of increasing steric bulk on their efficacy as ligands in gold(I)-catalyzed carbon–heteroatom bond-forming cyclizations has been investigated. Detailed solution NMR studies on Ph-TRISKITPHOS, its oxide, and the corresponding gold(I) chloride adduct identified a conformational exchange process involving a concerted librational motion of the individual anthracene-derived organic substituents about their P–C bonds. The cessation of this motion at reduced temperatures lowers the molecular symmetry such that the two C6H4 rings in each of the KITPHOS units become inequivalent; a lower energy process involving restricted rotation of the biaryl-like phenyl ring has also been identified. Electrophilic gold(I) complexes of these triaryl-like KITPHOS monophosphines catalyze the 5-exo-dig cycloisomerization of propargyl amides to afford the corresponding methylene oxazolines, which were used in a subsequent tandem carbonyl-ene reaction to afford functionalized 2-substituted oxazolines. A comparative survey revealed that catalyst efficiency for cycloisomerization decreases in the order MONOKITPHOS = BISKITPHOS > PPh3 > TRISKITPHOS. The optimum system also catalyzes the selective 6-endo-dig cyclization of 2-alkynylbenzyl alcohols, 2-alkynylbenzoic acid, and 2-phenylethynyl benzamides; gratifyingly, in several cases the yields obtained are markedly higher and/or reaction times significantly shorter than those previously reported for related gold catalysts. Moreover, these are the first examples of gold(I)-catalyzed 6-endo-dig cycloisomerizations involving 2-phenylethynyl benzamides and, reassuringly, the optimum gold(I)/MONOKITPHOS systems either rivaled or outperformed existing silver or palladium-based catalysts. The steric parameters of this homologous series of phosphines have been quantified and compared with selected triarylphosphines using a combination of Solid-G calculations, to determine the percentage of the metal coordination sphere shielded by the phosphine (the G parameter), and Salerno molecular buried volume calculations (SambVca) to determine the percent buried volume (%Vbur); the corresponding Tolman cone angles have also been determined from correlations.

2-Halogeno BODIPYs undergo copper catalysed nucleophilic substitution with alkyl amines and anilines and an amide to give the corresponding 3-aminoBODIPY derivatives. The substrates are readily prepared by the regioselective 2-halogenation of the chemically robust, preformed BODIPYs thus providing an alternative to direct nucleophilic substitution of the corresponding 3-halogenoBODIPYs which requires regioselective 3-halogenation of the more sensitive dipyrromethane intermediate. 2-Halogenation expands the scope of vicarious substitution of BODIPYs to include weaker nitrogen nucleophiles.

2-Halogeno BODIPYs undergo copper catalysed nucleophilic substitution with alkyl amines and anilines and an amide to give the corresponding 3-aminoBODIPY derivatives. The substrates are readily prepared by the regioselective 2-halogenation of the chemically robust, preformed BODIPYs thus providing an alternative to direct nucleophilic substitution of the corresponding 3-halogenoBODIPYs which requires regioselective 3-halogenation of the more sensitive dipyrromethane intermediate. 2-Halogenation expands the scope of vicarious substitution of BODIPYs to include weaker nitrogen nucleophiles.