Diastereoselective LiAlH4 reduction of chiral ketone hydrazones derived from (R)-(–)-2-aminobutan-1-ol
摘要:
Various chiral N,N-dialkylhydrazines were prepared in four to five steps from (R)-(-)-2-aminobutan-1-ol 6. They reacted with various prochiral ketones, thus giving the corresponding hydrazones. Reduction of the latter by means of LiAlH4 afforded N,N,N'-trisubstituted hydrazines whose d.e.s were in the range 43-100%. Interestingly, LiAlH4 reduction of the four N-trifluoroethylhydrazones 34 and 38-40 yielded the hydrazines 46 and 48-50, respectively, and with d.e.s = 100% by H-1 and C-13 NMR. (C) 2000 Elsevier Science Ltd. All rights reserved.
Enantioselective syntheses of α-phenylalkanamines via intermediate addition of Grignard reagents to chiral hydrazones derived from (R)-(−)-2-aminobutan-1-ol
作者:Patricia Bataille、Michel Paterne、Eric Brown
DOI:10.1016/s0957-4166(98)00217-1
日期:1998.6
The hydrazine (R)-(−)-28 was obtained in four steps from 2-aminobutan-1-ol (R)-(−)-11, and reacted with benzaldehyde to give the hydrazone (R)-(−)-29. Nucleophilic addition of various alkyl Grignardreagents to the latter yielded the corresponding trisubstituted hydrazines (R,R)-30a–g in 70–89% yields and having d.e.s=100% (1H and 13C NMR). Catalytic hydrogenolysis of these hydrazines afforded the
从2-氨基丁-1-醇(R)-(-)- 11通过四个步骤获得肼(R)-(-)- 28,并与苯甲醛反应得到the(R)-(-)-。29。向后者亲核添加各种烷基格氏试剂可得到相应的三取代肼(R,R)-30a - g,产率为70-89%,des = 100%(1 H和13 C NMR)。这些肼的催化氢解反应提供了相应的(R)-(+)-α-苯基链烷胺(R)-(+)- 31a – g ee = 90–92%(手性GPC)。
Diastereoselective LiAlH4 reduction of chiral ketone hydrazones derived from (R)-(–)-2-aminobutan-1-ol
作者:Patricia Bataille、Michel Paterne、Eric Brown
DOI:10.1016/s0957-4166(00)00044-6
日期:2000.3
Various chiral N,N-dialkylhydrazines were prepared in four to five steps from (R)-(-)-2-aminobutan-1-ol 6. They reacted with various prochiral ketones, thus giving the corresponding hydrazones. Reduction of the latter by means of LiAlH4 afforded N,N,N'-trisubstituted hydrazines whose d.e.s were in the range 43-100%. Interestingly, LiAlH4 reduction of the four N-trifluoroethylhydrazones 34 and 38-40 yielded the hydrazines 46 and 48-50, respectively, and with d.e.s = 100% by H-1 and C-13 NMR. (C) 2000 Elsevier Science Ltd. All rights reserved.