Synthesis of two-photon absorbing polyhydroxy diphenylamino-dialkylfluorene-1,3,5-triazine molecules

A method of synthesizing a two-photon active tris(diphenylamino-9,9-di(R)fluorenyl)-1,3,5-triazine compound having the structure:

• wherein the R′—(OY)x groups are attached to the phenyl rings of the triarylamine moiety in either a para position or a meta position, R′ of the R′—(OY)x group is a linear oxyalkylene group or a branched oxyalkylene group, Y of the R′—(OY)x is hydrogen or a tert-butyl (t—C4H9), and the subscript x of the —(OY)x is 1;
• and
• R is an alkyl group of the formula —CmH2m+1, wherein the subscript m ranges from 1 to 6, or an alkylether group of the formula —(CH2CH2O)pMe, wherein the subscript p ranges from 1 to 5, the method comprising:
• (a) synthesizing a diphenylamine intermediate by:
• (1) protecting each hydroxyl group of a bromophenoxy-propanol via a Mg(ClO4)2-catalyzed, ether-forming reactionwith di-tert butyl carbonate to generate the corresponding bromophenoxypropyl t-butyl ether compound;
• and
• (2) N-arylating aniline (C6H5NH2) with the corresponding bromophenoxylpropyl t-butyl ether compound by a palladium-catalyzed, N-Aryl coupling reaction;
• (b) synthesizing a tri-bromo-9,9-dialkylfluorenyl)-1,3,5-traizine intermediate by:
• (1) monoformylating 2,7-dibromo-9,9-di(R)fluorene to an aldehyde product;
• (2) converting the aldehyde product to a nitrile product;
• and
• (3) trimerizing the nitrile product in trifluoromethanesulfonic acid to the tris(bromo-dialkylfluorenyl)-1-3-5-triazine intermediate having a three-arm core;
• and
• (c) forming the two-photon active tris(diphenylamino-9,9-di(R)fluorenyl)-1,3,5-triazine polyhydroxy compound by:
• (1) N-arylating the diphenylamine intermediate to each arm of the three-arm core at the bromide position via palladium-catalyzed, N-Aryl coupling reaction;
• and
• (2) removing t-butyl moieties by acid hydrolysis or using a reagent mixture comprising a 1:1 mole ratio of vacuum-dried CeCl3 hydrate and NaI to expose each hydroxyl group of the corresponding tris(diphneylamino-9,9-di(R)fluorenyl)-1,3,5-triazine polyhydroxy compound.

A method of synthesizing a two-photon active tris(diphenylamino-9,9-di(R)fluorenyl)-1,3,5-triazine compound having the structure:

• wherein the R′—(OY)x groups are attached to the phenyl rings of the triarylamine moiety in either a meta position or a para position, R′ of the R′—(OY)x is linear or a branched oxyalkylene group, Y of the R′—(OY)x group is hydrogen or a tert-butyl (t—C4H9), and the subscript x of the -(OY)x is 3;and
• R is an alkyl group of the formula —CmH2m+1, wherein the subscript m ranges from 1 to 6, or an alkylether group of the formula —(CH2CH2O)pMe, wherein the subscript p ranges from 1 to 5, the method comprising:
• (a) synthesizing a diphenylamine intermediate by:
• (1) protecting each triol group of a bromophenyoxy-triol compound via a Mg(ClO4)2-catalyzed, ether-forming reaction with di-tert-butyl carbonate to generate the corresponding bromophenoxypropyl t-butyl ether compound;
• and
• (2) N-arylating aniline (C6H5NH2) with the corresponding bromophenoxy-tris(t-butyl ether) compound by a palladium-catalyzed, N-Aryl coupling reactions;
• (b) synthesizing a tris(bromo-dialkylfluorenyl)-1,3,5-triazine intermediate by:
• (1) monoformylating 2,7-dibromo-9,9-di(R)fluorene to an aldehyde product;
• (2) converting the aldehyde product to a nitrile product;
• and
• (3) trimerizing the nitrile product in trifluoromethanesulfonic acid to the brominated 1,3,5-triazine intermediate having a three-arm core;
• and
• (c) forming the two-photon active tris(diphenylamino-9,9-di(R)fluorenyl)-1,3,5-triazine polyhydroxy compound by:
• (1) N-arylating the diphenylamine intermediate to each arm of the three-arm core at the bromide position via a palladium-catalyzed N-Aryl coupling reactino;
• and
• (2) removing t-butyl moieties by acid hydrolysis or by using a regent mixture comprising a 1:1 mole ratio of vacuum-dried CeCl3 hydrate and Nal to expose each hydroxyl group of the corresponding tris(diphneylamino-9,9-di(R)fluorenyl)-1,3,5-triazine polyhydroxy compound.