Synthesis of C2-symmetrical chiral diamines: diastereoselective addition to bis(1,3-oxazolidinyl)alkanes with Grignard reagents
摘要:
Asymmetric syntheses of C-2-symmetrical chiral 1,4- and 1,5-diamines with stereogenic centers adjacent to the nitrogen atom have been accomplished. Chiral diamines were prepared by diastereoselective alkylations of bisoxazolidine, which was derived from (R)-phenylglycinol. Methyl and phenyl Grignard reagents were employed as alkylating reagents. In addition, tertiary chiral diamines were readily converted to primary diamines in high yield. (C) 2000 Elsevier Science Ltd. All rights reserved.
Synthesis of C2-symmetrical chiral diamines: diastereoselective addition to bis(1,3-oxazolidinyl)alkanes with Grignard reagents
摘要:
Asymmetric syntheses of C-2-symmetrical chiral 1,4- and 1,5-diamines with stereogenic centers adjacent to the nitrogen atom have been accomplished. Chiral diamines were prepared by diastereoselective alkylations of bisoxazolidine, which was derived from (R)-phenylglycinol. Methyl and phenyl Grignard reagents were employed as alkylating reagents. In addition, tertiary chiral diamines were readily converted to primary diamines in high yield. (C) 2000 Elsevier Science Ltd. All rights reserved.
GraphicsThe concise enantioselective total synthesis of C(2)-asymmetrical (-)-deoxocuscohygrine and (-)-dihydrocuscohygrine are described. Double-diastereoselective additions of normal Grignard reagent to bis(1.3-oxazolidine) have been deployed to construct chiral diamine fragments as a key step.
Synthesis of C2-symmetrical chiral diamines: diastereoselective addition to bis(1,3-oxazolidinyl)alkanes with Grignard reagents
Asymmetric syntheses of C-2-symmetrical chiral 1,4- and 1,5-diamines with stereogenic centers adjacent to the nitrogen atom have been accomplished. Chiral diamines were prepared by diastereoselective alkylations of bisoxazolidine, which was derived from (R)-phenylglycinol. Methyl and phenyl Grignard reagents were employed as alkylating reagents. In addition, tertiary chiral diamines were readily converted to primary diamines in high yield. (C) 2000 Elsevier Science Ltd. All rights reserved.