A short enantiospecific synthesis of 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene (ADTN)

Effective Synthesis of Optically Active Trifluoromethyldiazirinyl Homophenylalanine and Aroylalanine Derivatives with the Friedel-Crafts Reaction in Triflic Acid

“…(Fig. 1, Runs 3 and 4) Although the F-C reaction between N-aspartic anhydride derivatives and aromatics have been reported, [14][15][16][17][18][19] the aromatics had to be in excess amounts as the solvents. It would be preferable if we could use stoichiometric amounts of aromatics in the process by taking account of both the operational feasibility and economic matters.…”

Trifluoromethanesulfonic Acid as Acylation Catalyst: Special Feature for C- and/or O-Acylation Reactions

“…One of the potential skeletons used in the synthesis of aryl keto α-amino acids is formed by using aspartic anhydride 60, which can undergo direct C-acylation to arenes 61 under Friedel-Crafts conditions. When AlCl3 was used as the catalyst for the acylation of aspartic anhydrides with arenes, common organic solvents such as CH2Cl2 [40,41] or MeNO2 [41,42] were used under reflux for extended periods. When organic solvent was eliminated, arenes in excess amount were used because of their low solubility to solve some aspartic acid derivatives.…”

“…Catalysts 2017, 7, 40 16 of 27 solvent, resulting in high efficiencies of these reactions. When phenol 101 was reacted with 1 equiv.…”

“…Catalysts 2017, 7, 40 18 of 27 which affords good yields of the two isomers 109 and 110 (Table 3, entries 3 and 4). In summary, the controllability of TfOH catalysis in direct C-and/or O-acylations can be exploited to obtain the desired aromatic products from thermolabile substrates, an approach that would be of interest for further study.…”

Selective Hydrogenation and Transfer Hydrogenation for Post-Functional Synthesis of Trifluoromethylphenyl Diazirine Derivatives for Photoaffinity Labeling

“…Friedel-Crafts reactions between aromatics and a side chain of aspartic acid (Asp) or glutamic acid (Glu) are some of the key reactions for asymmetric synthesis for both homo-or bishomo-phenylalanine enantiomers' skeletons. (Reifenrath, et al 1976;Nordlander et al, 1985;Melillo et al, 1987;Griesbeck & Heckroth, 1997;Xu et al, 2000;Lin et al, 2001) It has been reported that synthesis of homophenylalanine using a Friedel-Crafts reaction of Asp anhydride (N-unprotected or N-protected) with AlCl3 requires use of large excesses of aromatics and reflux in organic solvent for long durations (Xie, et al, 2000). These synthesis conditions cannot apply the equivalent condition of amino acid and TPD derivatives.…”