Asymmetric Synthesis of <i>anti</i>-β-Amino-α-Hydroxy Esters via Dynamic Kinetic Resolution of β-Amino-α-Keto Esters
作者:C. Guy Goodman、Dung T. Do、Jeffrey S. Johnson
DOI:10.1021/ol4009206
日期:2013.5.17
method for the asymmetricsynthesis of enantioenriched anti-α-hydroxy-β-amino acid derivatives by enantioconvergent reduction of the corresponding racemic α-keto esters is presented. The requisite α-keto esters are prepared via Mannich addition of ethyl diazoacetate to imines followed by oxidation of the diazo group with Oxone. Implementation of a recently developed dynamickinetic resolution of β-substituted-α-keto
Asymmetric Aza-Morita-Baylis-Hillman Reactions of Alkyl Vinyl Ketones with N-Protected Imines or In Situ Generated N-Protected Imines
作者:Xiao-Yang Guan、Yin Wei、Min Shi
DOI:10.1002/ejoc.201000496
日期:2010.7
DABCO-catalyzed aza-MBH reactions of N-Boc imines with MVK and EVK have been thoroughly investigated in the paper. The asymmetric version of this aza-MBH reaction was also systematically investigated by using a chiral amine or a chiral phosphane catalyst. It was found that most of the N-protected imines are suitable substrates under the mild reaction conditions and are able to give the corresponding
DABCO 催化的 N-Boc 亚胺与 MVK 和 EVK 的 aza-MBH 反应已在论文中进行了彻底的研究。还通过使用手性胺或手性磷烷催化剂系统地研究了这种 aza-MBH 反应的不对称形式。发现大多数 N 保护的亚胺在温和的反应条件下是合适的底物,并且能够以中等产率和高 ee 值得到相应的加合物。TQO-或LB1-催化的N-保护的α-酰氨基烷基苯砜或α-酰氨基烷基对甲苯基砜与MVK的氮杂-MBH反应可以很好地进行,这为获得高对映选择性氮杂-MBH加合物提供了一种简便直接的途径.
Organocatalytic Asymmetric Mannich Reaction of 3-Hydroxyoxindoles/3-Aminooxindoles with in Situ Generated <i>N</i>-Boc-Protected Aldimines for the Synthesis of Vicinal Oxindole–Diamines/Amino Alcohols
A highly efficient asymmetricMannichreaction of 3-monosubstituted 3-aminooxindoles/3-hydroxyoxindoles with in situ generated N-Boc-protected aldimines catalyzed by the chiral bifunctional thiourea–tertiary amine catalyst has been developed. Under mild reaction conditions, a series of structurally diverse vicinal oxindole–diamines/amino alcohols were smoothly obtained in moderate to high yields (up
One-Pot Synthesis of α-Amino Acids from CO<sub>2</sub> Using a Bismetal Reagent with Si–B Bond
作者:Tsuyoshi Mita、Jianyang Chen、Masumi Sugawara、Yoshihiro Sato
DOI:10.1021/ol302952r
日期:2012.12.21
TsOH·H2O, precursors of N-Boc-imines can be converted into the corresponding α-aryl or α-alkenyl glycine derivatives under gaseous CO2 in moderate-to-high yields with a single operation. α-Isobutenyl glycine thus obtained can be further derivatized into various types of α-aminoacids including N-Boc-leucine, serine, and glycine derivatives in short steps.