Enantioselective Three-Step Synthesis of Homo-β-proline: A Donor–Acceptor Cyclopropane as Key Intermediate
作者:Ludwig K. A. Pilsl、Thomas Ertl、Oliver Reiser
DOI:10.1021/acs.orglett.7b01111
日期:2017.5.19
An enantioselective three-step synthesis of the GABA uptake inhibitor (S)-(+)-homo-β-proline was developed. The basis for the synthesis was the enantioselective CuI-catalyzed cyclopropanation of N-Boc-pyrrole, a substrate that persistently has proved to be challenging in such transformations. The cyclopropanation can be performed on a 150 mmol scale, and the two subsequent steps (i.e., hydrogenation
Chiral Bicyclic Guanidine as a Versatile Brønsted Base Catalyst for the Enantioselective Michael Reactions of Dithiomalonates and β-Keto Thioesters
作者:Weiping Ye、Zhiyong Jiang、Yujun Zhao、Serena Li Min Goh、Dasheng Leow、Ying-Teck Soh、Choon-Hong Tan
DOI:10.1002/adsc.200700326
日期:2007.11.5
A chiral bicyclic guanidine was developed as a versatile Brønsted base catalyst for the enantioselective Michael reactions of dithiomalonates and β-keto thioesters using a range of acceptors including maleimides, cyclic enones, furanone and acyclic 1,4-dicarbonylbutenes.
A convenient approach to diastereomerically pure 1,3,4-trisubstituted pyrrolidin-2-ones by intramolecular cyclisation of N-(2-alken-1-yl)amides mediated by Mn(III). An entry to both (R)- and (S)-3-pyrrolidineacetic acid
作者:Roberta Galeazzi、Giovanna Mobbili、Mario Orena
DOI:10.1016/0040-4020(95)00939-6
日期:1996.1
The oxidative cyclisation of a series of either (S)-N-(2-alken-1-yl)-N-(1-phenyleth-1-yl)-acetoacetamides5a-d and methoxycarbonylacetamides 6a-b, performed by using Mn(OAc)3 · 2H2) and Cu(OAc)2 · H2O in acetic acid, has been examined. The reaction proceeds regioselectively through a 5-exo-mode, leading to 1,3,4-trisubstituted pyrrolidin-2-ones 7a-d,8a-d and 9a-b,10a-b as diastereomeric mixtures in
使用Mn进行的一系列(S)-N-(2-烯-1-基)-N-(1-苯基乙基-1-基)-乙酰乙酰胺5a-d和甲氧羰基乙酰胺6a-b的氧化环化反应(OAc)3 ·2H 2)和Cu(OAc)2 ·H 2 O在乙酸中的含量已经过检验。该反应通过5- exo-模式区域选择性地进行,得到1,3,4-三取代的吡咯烷酮-2-酮7a-d,8a-d和9a-b,10a-b以约2:1的比例的非对映体混合物形式存在,其容易通过硅胶色谱法分离。由1 H NMR数据确定纯的非对映异构体的构型,并通过NOE实验确认。在分子力学计算的基础上解释了观察到的不对称感应。该环化构成了用于合成对映体纯形式(例如(R)-和(S)-3-吡咯烷乙酸)1和2均含有吡咯烷环的生物活性氨基酸的有用工具。
A convenient chemoenzymatic synthesis of (R)-(−) and (S)-(+)-homo-β-proline
Both enantiomers of the heterocyclic GABA analogue homo-β-proline (3-pyrrolidineacetic acid) were synthesized by a chemoenzymatic method involving the use of two enantiocomplementary enzymes in the disymmetric hydrolyses of 3-nitromethylglutaric acid diethyl ester.
The design, synthesis, and biological evaluation of a novel series of HIV-1proteaseinhibitors containing pyrrolidines with diverse linkers as the P2 ligands and various aromatic derivatives as the P2’ ligands were described. A number of inhibitors demonstrated potent efficacy in both enzyme and cellular assays, as well as relatively low cytotoxicity. In particular, inhibitor 34b with a (R)-pyrro