NHC-catalyzed [4 + 2] annulations of allenoates and 2,3-dioxopyrrolidine derivatives
作者:Xue Song、Yangxu Chen、Fangfang Lu、Kai Zhang、Chenxia Yu、Tuanjie Li、Changsheng Yao
DOI:10.1039/d1ob02180j
日期:——
A facile NHC-catalyzed [2 + 4] annulation of allenoates with 2,3-dioxypyrrolidine derivatives was discovered, which paved a new avenue for the construction of highly substituted pyranopyrrole with moderate to good yields, high atom economy and mild reaction conditions.
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
Au(I)/(<i>R</i>)-BINOL–Ti(IV) Concerted Catalyzed Asymmetric Cascade Cycloaddition Reaction of Arylalkynols
作者:Hongkai Wang、Tianlong Zeng、Weixing Chang、Lingyan Liu、Jing Li
DOI:10.1021/acs.orglett.1c00976
日期:2021.5.7
An efficient catalytic asymmetric cascade cycloadditionreaction of arylalkynols with dioxopyrrolidines was developed. This reaction was achieved using Au(I) and (R)-BINOL–Ti(IV) bimetallic catalysts and exclusively delivered a series of chiral oxo-bridged bicyclic benzooxacine compounds in up to 86% yield with 96% ee as well as >33:1 dr. Meanwhile, three new σ bonds and three new stereogenic centers
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。
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<sup>6</sup>
‐Arene CH−O Interaction Directed Dynamic Kinetic Resolution – Asymmetric Transfer Hydrogenation (DKR‐ATH) of α‐Keto/enol‐Lactams
作者:Zhonghua Luo、Guodong Sun、Shuming Wu、Yong Chen、Yicao Lin、Lei Zhang、Zhongqing Wang
DOI:10.1002/adsc.202100288
日期:2021.6.21
A dynamickinetic resolution – asymmetric transfer hydrogenation (DKR-ATH) methodology of α-keto/enol-lactams was developed. We also propose a possible catalytic mechanism evolving a transition state stabilized by η6-arene CH−O interaction. The efficient approach can be applied to a wide range of substrates including non-aryl ones which would be difficult to prepare by other asymmetric reduction methods