The use of 4,6-disubstituted pyrimidine-5-aldehydes in the synthesis of meso-tetraarylporphyrins

Synthesis and Functionalization of Double Picket Fence Porphyrins Starting from 4,6-Disubstituted Pyrimidine-5-carbaldehydes

“…The chlorine functionalities on the pyrimidine ring are highly activated toward nucleophilic substitution, allowing us to introduce substituents at the aldehyde as well as the porphyrin stage. 15 The aldehyde 1 was prepared using the reported Vilsmeier conditions (DMF/POCl 3 ) for chloroformylation of 4,6-dihydroxypyrimidine. 16 Functionalization of the two chlorine atoms of aldehyde 1 was carried out with several substituted phenolates.…”

“…The 4,6-dichloro-pyrimidine-5-carbaldehyde 1 can be considered as a heterocyclic analogue of 2,6-dichlorobenzaldehyde. The chlorine functionalities on the pyrimidine ring are highly activated toward nucleophilic substitution, allowing us to introduce substituents at the aldehyde as well as the porphyrin stage …”

“…Found: C,76.98;H,6.65;N,9.33. 5,10,15,20-Tetrakis[4,6-bis[3,5-bis(tert-butyl)phenoxy]-pyrimidin-5-yl]porphyrin (2c) was obtained from aldehyde 1c (0.500 g, 0.97 mmol) following the general procedure (0.135 g, 24%): 1 H NMR (400 MHz, CDCl3) δ -2.45 (s, 2H), 1.12 (s,-144H), 6.80 (d, J ) 1.6 Hz, 16H), 7.07 (d, J ) 1.6 Hz, 16H), 8.88…”

Sterically Encumbered Porphyrins by Suzuki Reactions of a 5,15-Bis(4,6-dichloropyrimidin-5-yl) Derivative

“…5,15-Bis(pyrimidinyl)porphyrin 1 (Scheme 1) was synthesized in a good yield of 53%. 8 The chlorine groups on the pyrimidine ring are highly activated towards nucleophilic aromatic substitution, allowing the preparation of a broad spectrum of porphyrins, including some extremely sterically hindered, true 'double picket fence' porphyrins. 9 By now applying Suzuki cross-coupling 7 reactions on this porphyrin, terphenyl-derived highly sterically encumbered porphyrins should be synthetically accessible.…”

ChemInform Abstract: A Short Total Synthesis of Cerpegin (VI) by Intramolecular Hetero Diels—Alder Cycloaddition Reaction of an Acetylene‐Tethered Pyrimidine.

“…1 We have recently used the readily available 2 4,6-dichloropyrimidine-5-aldehyde in connection with the synthesis of double picket-fence porphyrins. 3 It appeared to us that the electron poor dichloropyrimidine ring would be very reactive towards intramolecular cycloaddition when the appropriate tether is introduced at the 5-position. Only a few examples of intramolecular cycloadditions of 5-substituted pyrimidines were reported, 4 with most work concentrating on 2-substituted derivatives.…”