A flexible approach to construct three contiguous chiral centers of sphingolipids, and asymmetric synthesis of d-ribo-phytosphingosine and its derivatives
摘要:
An efficient approach to build the three contiguous stereogenic centers of sphingosine unit starting from cheap glutamic acid is described. The key step of this approach is the SmI2-mediated cross-coupling of chiral N-tert-butanesulfinyl imine 11 with sterically hindered aliphatic aldehyde 9 or 21 to construct hydroxymethyl beta-amino alcohol 10 or 22 in high diastereoselectivity (>99%, de). The utility of this flexible method has been demonstrated in the synthesis of D-ribo-phytosphingosine 1, its two derivatives 18 and 29. Moreover, a practicable synthetic route for synthesis of various sphingolipids, ceramides, alpha-galactosylceramides and their derivatives is also described. (c) 2012 Elsevier Ltd. All rights reserved.
报道了一种 Ni 催化的苯乙烯基氮丙啶与芳基碘化物的还原交叉偶联。该反应通过立体会聚机制进行,因此适用于使用 Ni 的手性生物恶唑啉配体进行不对称催化。该过程允许从外消旋氮丙啶轻松获得高度对映体富集的 2-芳基苯乙胺。多变量分析表明,配体极化率等特征会影响观察到的对映选择性,揭示了这种新兴配体类别在对映选择性 Ni 催化方面的成功。
Stereoselective Synthesis of β-Amino Ynones by the Addition of Alkynones to Nonracemic Sulfinimines: Formal Total Synthesis of <scp>l</scp>-<i>Xylo</i> and <scp>l</scp>-<i>Arabino</i> Phytosphingosines
作者:Polimera Obula Reddy、Arava Amaranadha Reddy、Kavirayani R. Prasad
DOI:10.1021/acs.joc.9b02938
日期:2020.2.21
sulfinimines furnished the corresponding β-sulfinamido ynones in a very good yield and diastereoselectivity. The formed ynones serve as precursors amenable for the synthesis of bioactive compounds. This has been illustrated in the synthesis of l-xylo and l-arabino phytosphingosines.
Stereoselective Addition of 2-Phenyloxazol-4-yl Trifluoromethanesulfonate to <i>N</i>-Sulfinyl Imines: Application to the Synthesis of the HCV Protease Inhibitor Boceprevir
作者:William J. Morris、Kiran K. Muppalla、Cameron Cowden、Richard G. Ball
DOI:10.1021/jo301856f
日期:2013.1.18
The stereoselective addition of 2-phenyloxazol-4-yl trifluoromethanesulfonate to N-sulfinylimines is described. Vinyl anions derived from enol triflate 2 undergo 1,2-addition with a variety of aldimines to afford the corresponding secondary sulfonamides as single diastereomers. The absolute stereochemistry was confirmed by X-ray crystallography which provides support that the reaction proceeds through
Concise Asymmetric Synthesis of Antimalarial Alkaloid (+)-Febrifugine
作者:Ming-Hua Xu、Guo-Qiang Lin、Rui Wang、Kai Fang、Bing-Feng Sun
DOI:10.1055/s-0029-1217713
日期:2009.9
An asymmetric total synthesis of antimalarialalkaloid (+)-febrifugine is accomplished in 23% overall yield over 14 steps from readily available starting materials. The synthesis features a Sml(2)-mediated reductive cross-coupling of chiral N-tert-butanesulfinyl imine with aldehyde.
Asymmetric [3+2] Annulation Approach to 3-Pyrrolines: Concise Total Syntheses of (−)-Supinidine, (−)-Isoretronecanol, and (+)-Elacomine
作者:Isaac Chogii、Jon T. Njardarson
DOI:10.1002/anie.201506559
日期:2015.11.9
short asymmetric total syntheses of (−)‐supinidine, (−)‐isoretronecanol, and (+)‐elacomine. This novel annulation approach also works for an aldehyde, thus providing access to a 2,5‐dihydrofuran product in a single step from simple precursors. By modifying the structure of the carbanion nucleophile, an asymmetric vinylogous aza‐Darzens reaction can be realized.
The present invention relates to various organic reactions including a method for producing heterocyclic compounds using a [3+2] annulation; a method for producing fluorinated heteroaromatic compounds; and a method for alkylating a meta-position of a phenolic compound. In one aspect of the invention, a method is provided for producing a 3-pyrroline compound by reacting an chiral imine with an enoate containing a leaving group at the gamma position.