Synthesis of substituted salicylaldehyde derivatives
Among other things, the present invention encompasses methods of synthesizing salicylaldehyde derivatives comprising the steps of: a) providing salicylaldehyde or a derivative thereof, b) forming an anhydro dimer of the provided salicylaldehyde compound, c) performing one or more chemical transformations on the anhydro dimer and d) hydrolyzing the anhydro dimer to provide a salicylaldehyde derivative different from that provided in step (a).
1. A compound of any one of formulae D14 to D18:
wherein,
R 26 is selected from the group consisting of: hydrogen, halogen, optionally substituted C 1-20 aliphatic, and optionally substituted aryl;
R a and R b are, independently at each occurrence, selected from the group consisting of hydrogen, halogen, and optionally substituted C 1-4 aliphatic;
Q′ is selected from the group consisting of: halogen, hydroxyl, sulfonate ester, a neutral or cationic nitrogen-containing functional group, and a neutral or cationic phosphorous-containing functional group; and
m is from 1 to 10.
2. The compound of claim 1 , wherein Q′ is selected from the group consisting of: bromine, chlorine, iodine, —OH, —OSO 2 R, —N(R) 2 , —N(R) 3 + , —P(R) 3 + , substituted guanidine, guanidinium, and amidine; wherein R is hydrogen; C 1 -C 20 alkyl; C 1 -C 20 alkyl having one or more functional moieties selected from the group consisting of halogen, nitrogen, oxygen, silicon, sulfur, and phosphorus; C 2 -C 20 alkenyl; C 2 -C 20 alkenyl having one or more functional moieties selected from the group consisting of halogen, nitrogen, oxygen, silicon, sulfur, and phosphorus; C 7 -C 20 alkylaryl; C 7 -C 20 alkylaryl having one or more functional moieties selected from the group consisting of halogen, nitrogen, oxygen, silicon, sulfur, and phosphorus; C 7 -C 20 arylalkyl; and C 7 -C 20 arylalkyl having one or more functional moieties selected from the group consisting of halogen, nitrogen, oxygen, silicon, sulfur, and phosphorus.
3. The compound of claim 2 , wherein Q′ is —OH.
4. The compound of claim 2 , wherein Q′ is bromine.
5. The compound of claim 1 , wherein Q′ is a guanidine.
6. The compound of claim 5 , wherein Q′ is 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD).
7. The compound of claim 2 , wherein Q′ is 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene ([N-methyl TBD] + ).
8. The compound of claim 2 , wherein Q′ is trialkylammonium.
9. The compound of claim 1 , wherein R 26 is selected from the group consisting of: —H, halogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, and t-butyl.
10. The compound of claim 9 , wherein R 26 is t-butyl.
11. The compound of claim 1 , wherein m is an integer between 1 and 6.
12. The compound of claim 9 , wherein Q′ is TBD.
13. The compound of claim 9 , wherein Q′ is [N-methyl TBD] + .