An unprecedented strategy to access highly enantioenriched dihydropyrazoles is described. It involves formal [4+1] cycloadditions of in situ-derived azoalkenes and sulfurylides catalyzed by a chiral copper/Tol-BINAP complex. A variety of synthetically and biologically important dihydropyrazoles have been obtained with high enantioselectivities (up to 97:3 er) in good yields (83-97%).
benzoxazinanones (4) with sulfur ylides (2) is reported. While the reactions of 4-vinyl/4-CF3 benzoxazinanones (1a/1c) with 2 furnished the 3-vinyl/3-CF3 indolines (3a/3c), via an attack on the C1 carbon of the π-allyl/benzyl zwitterionic intermediates, 4 was converted into 4-trifluoromethyl-dihydroquinolines (5) in good yields via an attack on the C3 carbon of the π-allyl intermediate. The corresponding
A visible-light-driven and room temperature photo-Wolff-Kischner reaction of sulfur ylides and N-tosylhydrazones has been developed for the first time to provide modular access to alkene synthesis. The high functional group tolerance and broad substrate scope were demonstrated by more than 60 examples. Both E- and Z-olefinic stereochemistry in the products could be controlled with excellent stereoselectivity
Batting the ylides: A simple procedure carried out under mild conditions allows the direct and efficientsynthesis of structurally diverse indoles. This approach involves a cascadereaction of sulfurylides and N‐(ortho‐chloromethyl)arylamides (see scheme).
Highly Diastereoselective Synthesis of Trifluoromethyl Indolines by Interceptive Benzylic Decarboxylative Cycloaddition of Nonvinyl, Trifluoromethyl Benzoxazinanones with Sulfur Ylides under Palladium Catalysis
diastereoselective synthesis of trifluoromethyl-substituted indolines under palladium catalysis is disclosed. The reaction proceeds by interceptive decarboxylative benzylic cycloaddition (IDBC) of nonvinyl, trifluoromethyl benzoxazinanones with sulfur ylides. The palladium−π-benzyl zwitterionic intermediates are suggested for this transformation, and this would be the first example of an IDBC reaction.