The mysterious cyclizations of gold: An asymmetric gold(I)‐catalyzed formal [3+3] cycloaddition of 2‐(1‐alkynyl)‐2‐alken‐1‐ones with nitrones has been developed. Compound 1 was found to be an effective and reliable chiral catalyst, as well as the commonly used 2, for this gold‐catalyzed reaction. Tf=trifluoromethanesulfonyl.
Tetrasubstituted furans by PdII/CuI-cocatalyzed three-component domino reactions of 2-(1-alkynyl)-2-alken-1-ones, nucleophiles and diaryliodonium salts
作者:Wenbo Li、Junliang Zhang
DOI:10.1039/c0cc03450a
日期:——
A novel Pd(OAc)(2)/CuI-cocatalyzed three-componentreaction of 2-(1-alkynyl)-2-alken-1-ones, nucleophiles and diaryliodonium salts has been developed. The procedure allows the synthesis of tetrasubstitutedfurans in good to high yields under mild conditions.
A Base-Promoted Tandem Cycloaddition/Air Oxidation Reaction of Electron-Deficient Conjugated Enynes and Hydrazines: Synthesis of Highly Substituted Pyrazoles
作者:Xiuzhao Yu、Junliang Zhang
DOI:10.1002/chem.201202583
日期:2012.10.8
Rapid access: A base‐mediated cycloaddition/oxidationreaction of hydrazines and electron‐deficient 1,3‐conjugatedenynes gives pyrazole derivatives, some of which are not easily accessible by other methods (see scheme). The reaction conditions are mild, thus enabling a variety of functional groups to be tolerated.
Gold(I)-Catalyzed, Highly Diastereoselective, Tandem Heterocyclizations/[3+2] Cycloadditions: Synthesis of Highly Substituted Cyclopenta[c]furans
作者:Hongyin Gao、Xingxing Wu、Junliang Zhang
DOI:10.1002/chem.201003363
日期:2011.3.1
The domino effect: A novel, cationic, gold(I)‐catalyzed [3+2], tandem bicyclization, which provides rapid, efficient, and diastereoselective access to highly substituted cyclopenta[c]furans from simple, readily available 2‐(1‐alkynyl)‐2‐alken‐1‐ones and 3‐styrylindoles under mild conditions, is described (see scheme).