Asymmetric Organocatalytic One-Pot, Two-Step Sequential Process to Synthesize Chiral Acetal-Containing Polycyclic Derivatives from Cyclic Hemiacetals and Enones
作者:Chao Liu、Yan-Kai Liu
DOI:10.1021/acs.joc.7b01915
日期:2017.10.6
synthesize biologically and synthetically important chiral acetal-containing polycyclic derivatives. This novel protocol had been proved to proceed via Michael-lactolization-oxocarbenium ion ring-closing sequence, which was initiated by a key reactive enamine intermediate and interrupted the previously established reaction pathway of two different enones used in this work, and generated the corresponding
NHC-Catalyzed Asymmetric α-Regioselective [4 + 2] Annulation to Construct α-Alkylidene-δ-lactones
作者:Lala Liu、Donghui Guo、Jian Wang
DOI:10.1021/acs.orglett.0c02573
日期:2020.9.4
The unprecedented NHC-catalyzed [4 + 2] annulation of α-bromoenals with dioxopyrrolidines is described. This protocol features broad substrate scope and allows rapid assembly of α-alkylidene-δ-lactones in good to high yields with excellent enantioselectivities. Notably, this process includes α-regioselective activation of azolium dienolate intermediates, which has not yet been reported.
A silver-catalyzed domino inverse electron-demand oxo-Diels–Alder reaction of 3-cyclopropylideneprop-2-en-1-ones with 2,3-dioxopyrrolidines <i>via</i> cyclobutane-fused furan
作者:Yanshun Zhang、Yin Wei、Min Shi
DOI:10.1039/d1cc00707f
日期:——
silver-catalyzed diastereoselective one-pot domino cyclization-migration/inverse electron-demand oxo-Diels–Alder reaction has been disclosed in this communication through the in situ generated cyclobutane-fused furan intermediate with 4-vinyl-2,3-dioxopyrrolidine for the construction of 2-oxopyrrolidine-fused tricyclic compounds in moderate to good yields with a broad substrate scope under mild conditions
Organocatalytic Asymmetric Inverse‐Electron‐Demand Diels‐Alder Reaction of Pyrrolidone‐Dienes with Enals
作者:Shu‐Xiao Wu、Bo‐Qi Gu、Hui Xu、Xing Zheng、Xiaoyan Luo、Wei‐Ping Deng
DOI:10.1002/adsc.201900664
日期:2019.9.17
A new pyrrolidone‐diene synthon was devised, and the inverse‐electron‐demand Diels‐Alderreaction of pyrrolidone‐dienes with enals catalyzed by chiral secondary amines has been disclosed. A variety of enantioenriched, multifunctionalized hexahydro‐isoindol‐1‐one derivatives were obtained in good yields (up to 75%) with excellent stereoselectivities (up to >20:1 dr and >99% ee).
Enantioselective synthesis of pyrano[2,3-<i>c</i>]pyrrole <i>via</i> an organocatalytic [4 + 2] cyclization reaction of dioxopyrrolidines and azlactones
cyclization reaction of dioxopyrrolidines and azlactones has been successfully developed through a squaramide catalysis strategy. This protocol provides an efficient and mild access to obtain pyrano[2,3-c]pyrrole scaffolds containing contiguous quaternary and tertiary stereogenic centers in excellent yields (up to 99%) with high levels of diastereo- and enantioselectivities (up to 99% ee). Two possible pathways
二氧吡咯烷和氮杂内酯的对映选择性[4 + 2]环化反应已通过方酰胺催化策略成功开发。该协议提供了高效,温和的途径来获得吡喃并[2,3- c ]吡咯支架,该支架包含连续的四级和三级立体异构中心,产率高(高达99%),非对映和对映选择性高(ee高达99%) )。提出了两种可能的途径来解释观察到的立体选择性。