of a method for addition of trimethylsilylcyanide to chiral oxazolidinone-derived N-acylhydrazones is described. The diastereoselectivity was found to be highly dependent on the substituent of the oxazolidinone moiety; 4-phenyl-2-oxazolidinone achieved much higher stereocontrol than four other oxazolidinones screened. The reaction gives modest selectivity with aliphatic hydrazones and excellent selectivity
Highly Diastereoselective Indium-Mediated Allylation of Chiral Hydrazones
作者:Gregory R. Cook、Bikash C. Maity、Robert Kargbo
DOI:10.1021/ol0496172
日期:2004.5.1
The indium-mediated allylation of chiral hydrazones was investigated. Essentially complete diastereoselectivity and quantitative yields were obtained for substrates derived from both aromatic and aliphatic aldehydes. [reaction--see text]
Comparison of Electrophilic Amination Reagents for N-Amination of 2-Oxazolidinones and Application to Synthesis of Chiral Hydrazones
作者:Yuehai Shen、Gregory K. Friestad
DOI:10.1021/jo0259663
日期:2002.8.1
Comparison of several hydroxylamine-based electrophilic ammonia equivalents in the N-amination of 2-oxazolidinones revealed that O-(p-nitrobenzoyl)hydroxylamine (NbzONH(2)) and sodium hydride in dioxane is a superior reagent combination for this purpose. Practical preparations of a variety of chiral N-acylhydrazones by this method gave yields ranging from 45 to 95%. Methods for exchange or removal