Synthesis of 3-Pyrrolin-2-ones by Rhodium-Catalyzed Transannulation of 1-Sulfonyl-1,2,3-triazole with Ketene Silyl Acetal
作者:Rui-Qiao Ran、Jun He、Shi-Dong Xiu、Kai-Bing Wang、Chuan-Ying Li
DOI:10.1021/ol501514b
日期:2014.7.18
α-Imino rhodium carbenoids generated from 1-sulfonyl 1,2,3-triazole were applied to the 3 + 2 cycloaddition with ketene silyl acetal, offering a novel and straightforward synthesis of biologically interesting compound 3-pyrrolin-2-one with broad substrate scope.
Sc(OTf)<sub>3</sub>-Catalyzed C–C Bond-Forming Reaction of Cyclic Peroxy Ketals for the Synthesis of Highly Functionalized 1,2-Dioxene Endoperoxides
作者:Haowei Feng、Yukun Zhao、Pengkang Liu、Lin Hu
DOI:10.1021/acs.orglett.1c00056
日期:2021.3.5
A new and general Sc(OTf)3-catalyzed C–C bond-forming reaction of 3-(2-methoxyethoxy)-endoperoxy ketals with silyl ketene acetals, silyl enol ethers, allyltrimethylsilane, and trimethylsilyl cyanide has been developed via the reactive peroxycarbenium ions, affording a wide range of complicated 3,3,6,6-tetrasubstituted 1,2-dioxenes bearing adjacent quaternary carbons and 3-acetyl/allyl/cyano functional
Pentafluorophenylammonium Trifluoromethanesulfonimide: Mild, Powerful, and Robust Catalyst for Mukaiyama Aldol and Mannich Reactions between Ketene Silyl Acetals and Ketones or Oxime Ethers
(C6F5N+H3⋅NTf2−) promotes Mukaiyama aldol and Mannich reactions using ketenesilylacetals with ketones and oxime ethers, respectively. The present robust method is mild, but powerful enough to utilize less accessible electrophiles such as enolizable ketones and oxime ethers to produce a variety of β‐hydroxy esters and β‐alkoxyamino esters, respectively. Mechanistic investigation revealed in situ generation
InBr
<sub>3</sub>
‐Catalyzed Coupling Reaction between Electron‐Deficient Alkenyl Ethers with Silyl Enolates for Stereoselective Synthesis of 1,5‐Dioxo‐alk‐2‐enes
InBr3 catalysis enables the coupling between 2‐carbonylalkenyl ethers and silyl enolates to give 1,5‐dioxo‐alk‐2‐enes featuring alkene moieties with perfect stereoselectivity. Various types of 2‐carbonylalkenyl ethers and silyl enolates are applicable to the present reaction. InBr3 with moderate Lewis acidity plays an important role in both the activation of alkenyl ethers and in the elimination of
(Z)-β-Aryloxyalkenylzincs are synthesized stereoselectively via anti-carbozincation among alkynyl ethers, silyl ketene acetals, and ZnBr2. X-ray analysis revealed the structure of the zinc species is a mononuclear two-coordinate dialkenylzinc that is transformed into functionalized enol ethers as a single isomer in the reaction of various electrophiles.