Amidation of Esters with Amino Alcohols Using Organobase Catalysis
作者:Nicola Caldwell、Peter S. Campbell、Craig Jamieson、Frances Potjewyd、Iain Simpson、Allan J. B. Watson
DOI:10.1021/jo501929c
日期:2014.10.3
the base-mediated amidation of unactivated esters with amino alcohol derivatives is reported. Investigations into mechanistic aspects of the process indicate that the reaction involves an initial transesterification, followed by an intramolecular rearrangement. The reaction is highly general in nature and can be extended to include the synthesis of oxazolidinone systems through use of dimethyl carbonate
Asymmetric conjugate addition of Grignard reagents in the presence of tertiary amines to α,β-unsaturated amides derived from (S)-2-(1-hydroxy-1-methylethyl)pyrrolidine or (S)-prolinol
作者:Kenso Soai、Hideaki Machida、Atsuhiro Ookawa
DOI:10.1039/c39850000469
日期:——
In the presence of tertiaryamines, diastereoselective conjugateaddition of Grignardreagents to α,β-unsaturatedamides affords 3-substituted carboxylic acids of high enantiomeric excess (up to 89% e.e.).
Conjugateadditions of MeCu, PhCu and BuCu to the chiral enoylimides 2 a-c in the presence of iodotrimethylsilane and lithium iodide in THF give the adducts, 4a-c in yields above 90 % and diastereoselectivities from 80 to 93%. The dominating diastereomers are different from those formed with LiR2Cu/TMSCl or in copper(I)-mediated addition of Grignard reagents. Corresponding additions to enoylamides
在THF中存在碘三甲基硅烷和碘化锂的情况下,将MeCu,PhCu和BuCu共轭添加到手性烯丙酰亚胺2 ac中,得到加合物4a-c,收率超过90%,非对映选择性为80%至93%。占主导地位的非对映异构体不同于由LiR 2 Cu / TMSCl形成的非对映异构体,或在铜(I)介导的格氏试剂中添加的非对映异构体。邻三苯甲基脯氨醇向烯酰胺中的相应添加也可产生高产率的共轭加合物,但非对映选择性较低,酰基部分的主要构型与酰亚胺相反。
De Sarkar, Suman; Grimme, Stefan; Studer, Armido, Journal of the American Chemical Society, 2010, vol. 132, p. 1190 - 1191
作者:De Sarkar, Suman、Grimme, Stefan、Studer, Armido
DOI:——
日期:——
α-Amino acids as chiral educts for stereoselective syntheses of pyrrolidine and pyrrolizidine systems
Homochiral functionalized pyrrolidine and pyrrolizidine systems have been achieved by stereoselective intramolecular 1,3-dipolar cycloaddition of homochiral nitrones, starting from homochiral amino acids, and by subsequent reduction of the obtained cycloadducts.