Stereoselective Synthesis of C₆₀-Based Cyclopropane Amino Acids

Recent progress on the stereoselective synthesis of cyclic quaternary α-amino acids

“…Cleavage of the N -Boc protective group of 384 with TMSI in chloroform led to compound 385 in 89% yield (Scheme 83). 182…”

Cycloadditions

“…Isoxazoline derivatives of C 60 such as 250 (Scheme 4.40) are accessible by 1,3-dipolar cycloadditions of nitrile oxides to [6,6] double bonds of the fullerene [2, 278,[291][292][293][294][295][296][297][298][299][300][301][302][303][304][305]. The nitrile oxides 249 with R = methyl, ethyl, ethoxycarbonyl and anthryl are generated in situ from the corresponding nitroalkane, phenyl isocyanate and triethylamine.…”

“…Isoxazolines of C 60 and C 70 [293][294][295] with R = Ph, alkyl, 4-C 6 H 4 OCH 3, 4-C 6 H 4 CHO, amino acid [305], dialkoxyphosphoryl [296,297] or ferrocene [298] have been synthesized in ca. Hydroxymoyl chlorides are accessible by the reaction of aldoximes with chlorinating agents such as NCS (N-chlorosuccinimide).…”

An Approach to Nanobioparticles – Synthesis and Characterization of Fulleropeptides

“…[18] Amino acids and peptides are crucial building blocks of all living organisms and their conjugation with fullerene attracts a lot of scientific interest. [19][20][21][22] Syntheses of C 60 -containing amino acids are mainly based on different addition reaction of suitable substrates to the fullerene (cyclopropanation, [23][24][25] [3+2] [26][27][28] and [4+2] cycloadditions [29][30][31] ). The biggest unnatural amino acid so far reported, fulleroproline, was obtained by 1,3-dipolar cycloaddition of an azomethine ylide to C 60 , [32] whereas a methanofullerene-substituted amino acid prepared by cyclopropanation of C 60 was the starting material for the first fulleropeptide.…”