578741-04-5Relevant articles and documents
Aziridination of C60 with simple amides and catalytic rearrangement of the aziridinofullerenes to azafulleroids
Tsuruoka, Ryoji,Nagamachi, Toshiki,Murakami, Yuta,Komatsu, Mitsuo,Minakata, Satoshi
supporting information; experimental part, p. 1691 - 1697 (2009/07/30)
The selective formation of aziridinofullerene and azafulleroid, which are isomers of the fullerene derivatives-introduced N1 unit, is achieved. The ionic aziridination is a very convenient and risk-free procedure compared with the conventional
Enzyme-catalyzed enantiomeric resolution of N-Boc-proline as the key-step in an expeditious route towards RAMP
Kurokawa, Masayuki,Shindo, Takeyuki,Suzuki, Masumi,Nakajima, Nobuyoshi,Ishihara, Kohji,Sugai, Takeshi
, p. 1323 - 1333 (2007/10/03)
For the preparation of both enantiomers of N-carbamoyl-2-methoxymethylpyrrolidine, the precursors of Enders' chiral auxiliaries, SAMP and RAMP, enzyme-catalyzed kinetic resolution of racemic N-carbamoyl, N-Boc, N-Cbz proline esters and prolinols were examined. B. licheniformis protease (subtilisin) preferentially hydrolyzed the (R)-carbamoylproline ester with an enantiomeric ratio (E) of 10. To a hydrophobic N-Cbz proline ester, subtilisin showed lower selectivity (E=2.8), and in contrast, a purified protease (isozyme A) from the earthworm showed the preference of (S)-enantiomer (E=13.6). In a practical sense, C. antarctica lipase B (Chirazyme L-2) was effective for the hydrolysis of both N-Boc and N-Cbz derivatives with E >100. The e.e. of (R)-N-carbamoyl-2-methoxymethylpyrrolidine was raised to be >99.9% by recrystallization at the N-Boc-prolinol stage, which was derived from the (R)-N-Boc-proline methyl ester (98.7% e.e.) through a preparative-scale enzyme-catalyzed resolution (49% yield) of the racemic substrate.
