A simple and practical synthesis of ynones directly from readily available aldehydes was developed for the first time under mild reaction conditions via a Rh(III)- or Ir(III)-catalyzed formyl C-H bondactivation.
Diastereoselective Synthesis of Tetrahydroquinolines Bearing Oxindole Scaffolds via Annulation of
<i>in Situ</i>
Generated
<i>p</i>
‐Quinone Methides
作者:Junwei Wang、Lei Zhao、Lin Zhao、Xiang Pan、Cheng Lv、Ying Zhi、Ai Wang、Kun Zhao、Lihong Hu
DOI:10.1002/adsc.202000436
日期:2020.7.16
diastereoselective [4+2] annulation reaction between in situ generated p‐quinonemethides and isatin‐derived enoates has been developed. In the presence of manganese dioxide as an oxidant, a variety of tosylaminophenyl‐substituted p‐quinonemethide intermediates can be readily generated in an in situ fashion. Without pre‐preparation of p‐QMs, this unprecedented cascade reaction proceeds efficiently under
Carbene insertion into acyl C-H bonds: Rh(III)-catalyzed cross-coupling of 2-aminobenzaldehydes with conjugated enynones
作者:Yifan Ping、Taiwei Chang、Jianbo Wang
DOI:10.1016/j.tet.2021.132274
日期:2021.7
A rhodium-catalyzed directed acyl C-H bonds carbeneinsertion reaction of 2-aminobenzaldehydes with conjugated enynones has been realized, affording a series of α-furyl ketone derivatives in moderate to good yields with good functional group tolerance. Carbene migratory insertion is proposed as the key step in this transformation.
Phosphine-Catalyzed α-Umpolung–Aldol Reaction for the Synthesis of Benzo[<i>b</i>]azapin-3-ones
作者:Kui Zhang、Lingchao Cai、Sooji Hong、Ohyun Kwon
DOI:10.1021/acs.orglett.9b01749
日期:2019.7.5
serves as a conduit for the construction of benzo[b]azepin-3-ones in good to excellent yields under mild conditions. The resulting 2-benzylidene moieties are formed exclusively in the E-configuration. Mechanistically, this unusual annulation occurs through a phosphine-catalyzed α-umpolung addition, followed by an aldol reaction. One of the benzo[b]azepin-3-one products was converted to the core structure
报道了一种新型膦催化的 2-磺酰胺苯甲醛和炔酮之间的分子间环化。该方法可作为在温和条件下以良好至优异的产率构建苯并[ b ]氮杂-3-酮的渠道。所得的2-亚苄基部分仅以E-构型形成。从机制上讲,这种不寻常的环化是通过膦催化的 α-umpolung 加成,然后是羟醛反应发生的。其中一种苯并[ b ]氮杂卓-3-酮产品被转化为3-氨基-[ a ]苯并氮杂卓-2-一-1-链烷酸的核心结构,其中许多充当血管紧张素转换酶抑制剂。
作者:Kui Zhang、Lingchao Cai、Zhongyue Yang、K. N. Houk、Ohyun Kwon
DOI:10.1039/c7sc04381c
日期:——
A novel bridged [2.2.1] bicyclic phosphineoxide, devised to circumvent the waste generation and burdens of purification that are typical of reactions driven by the generation of phosphineoxides, has been prepared in three steps from commercially available cyclopent-3-ene-1-carboxylic acid. The performance of this novel phosphineoxide was superior to those of current best-in-class counterparts, as