Direct, enantioselective synthesis of pyrroloindolines and indolines from simple indole derivatives
作者:Jane Ni、Haoxuan Wang、Sarah E. Reisman
DOI:10.1016/j.tet.2013.04.003
日期:2013.7
The (R)-BINOL·SnCl4-catalyzed formal (3+2) cycloaddition between 3-substituted indoles and benzyl 2-trifluoroacetamidoacrylate is a direct, enantioselective method to prepare pyrroloindolines from simple starting materials. However, under the originally disclosed conditions, the pyrroloindolines are formed as mixtures of diastereomers, typically in the range of 3:1 to 5:1 favoring the exo-product. The
( R )-BINOL·SnCl 4催化的 3-取代吲哚与 2-三氟乙酰氨基丙烯酸苄酯之间的形式 (3+2) 环加成反应是一种直接的、对映选择性的方法,可从简单的起始原料制备吡咯并二氢吲哚。然而,在最初公开的条件下,吡咯并二氢吲哚形成为非对映异构体的混合物,通常在3:1至5:1的范围内,有利于外型产物。差的非对映选择性有损于反应的合成效用。我们在此报告了 2-三氟乙酰氨基丙烯酸甲酯与 ( R )-3,3'-二氯-BINOL·SnCl 4 结合使用提供具有改进的非对映选择性(通常≥10:1)的相应吡咯并二氢吲哚。在机理研究的指导下,还描述了通过原位还原持久性亚胺离子来合成富含对映体二氢吲哚的单瓶合成。
Stereoselective Michael additions on α-aminoacrylates as the key step to an<scp>l</scp>-Oic analogue bearing a quaternary stereocenter
作者:Federico Maria Cecchinelli、Giuseppe Celentano、Alessandra Puglisi、Nicoletta Gaggero
DOI:10.1039/c9ob02084e
日期:——
A novel, highly stereoselective route for pharmaceutically relevant octahydroindole-2-carboxylates bearing a quaternarystereocenter has been developed. The key chiral intermediates 3 have been prepared in good yields and enantiomeric excesses up to 98%. A broad substrate range has been tolerated under the reaction conditions.
Enantioselective Synthesis of Tryptophan Derivatives by a Tandem Friedel–Crafts Conjugate Addition/Asymmetric Protonation Reaction
作者:Madeleine E. Kieffer、Lindsay M. Repka、Sarah E. Reisman
DOI:10.1021/ja209390d
日期:2012.3.21
tandem Friedel-Crafts conjugate addition/asymmetric protonation reaction between 2-substituted indoles and methyl 2-acetamidoacrylate is reported. The reaction is catalyzed by (R)-3,3'-dibromo-BINOL in the presence of stoichiometric SnCl(4), and is the first example of a tandem conjugate addition/asymmetric protonation reaction using a BINOL·SnCl(4) complex as the catalyst. A range of indoles furnished
Enantioselective Total Synthesis of (−)-Lansai B and (+)-Nocardioazines A and B
作者:Haoxuan Wang、Sarah E. Reisman
DOI:10.1002/anie.201402571
日期:2014.6.10
The concise totalsyntheses of the bis(pyrroloindolines) (−)‐lansai B and (+)‐ nocardioazines A and B are reported. The key pyrroloindoline building blocks are rapidly prepared by enantioselective formal [3+2] cycloaddition reactions. The macrocycle of (+)‐nocardioazine A is constructed by an unusual intramolecular diketopiperazine formation.
报道了双(吡咯并吲哚啉)(-)-lansai B 和(+)-nocardioazines A 和 B 的简明全合成。关键的吡咯并二氢吲哚结构单元是通过对映选择性形式的 [3+2] 环加成反应快速制备的。(+)-nocardioazine A 的大环由不寻常的分子内二酮哌嗪形成构成。
Enantioselective Synthesis of Pyrroloindolines by a Formal [3 + 2] Cycloaddition Reaction
作者:Lindsay M. Repka、Jane Ni、Sarah E. Reisman
DOI:10.1021/ja107328g
日期:2010.10.20
(R)-BINOL·SnCl(4) was found to catalyze a formal [3 + 2] cycloaddition reaction between C(3)-substituted indoles and 2-amidoacrylates to provide pyrroloindolines. A variety of pyrroloindolines were prepared with high enantioselectivity in one step from simple precursors. This methodology is expected to facilitate the total synthesis of pyrroloindoline alkaloids, an important class of biologically active