A RhIII‐catalyzed intramolecularoxidative cross‐coupling between double bonds for the synthesis of macrolides is described. Under the optimized reaction conditions, macrocycles containing a diene moiety can be formed in reasonable yields and with excellent chemo‐ and stereoselectivity. This method provides an efficient approach to synthesize macrocyclic compounds containing a 1,3‐conjugated diene
Pd-catalyzed α-olefinic C-H activation of simple α,β-unsaturated olefins has been developed. 4-imino-β-lactam derivatives were readily synthesized via activation of α-olefinic C-H bonds with excellent cis stereoselectivity. A wide range of heterocycles at the β-position are compatible with this reaction. The product of 4-imino-β-lactam derivatives can be readily converted to 2-aminoquinoline which
Enantioselective 1,3-Dipolar Cycloadditions of Diazoacetates with Electron-Deficient Olefins
作者:Mukund P. Sibi、Levi M. Stanley、Takahiro Soeta
DOI:10.1021/ol070364x
日期:2007.4.1
[reaction: see text] A general strategy for highly enantioselective 1,3-dipolarcycloaddition of diazoesters to beta-substituted, alpha-substituted, and alpha,beta-disubstituted alpha,beta-unsaturated pyrazolidinone imides is described. Cycloadditions utilizing less reactive alpha,beta-disubstituted dipolarophiles require elevated reaction temperatures, but still provide the corresponding pyrazolines
Intramolecular Nitrofuran Diels–Alder Reactions: Extremely Substituent-Tolerant Cycloadditions via Asynchronous Transition States
作者:Thomas Y. Cowie、Marcos Veguillas、Robert L. Rae、Mathilde Rougé、Justyna M. Żurek、Andrew W. Prentice、Martin J. Paterson、Magnus W. P. Bebbington
DOI:10.1021/acs.joc.7b00781
日期:2017.7.7
Nitrofurans undergo intramolecularDiels–Alderreactions with tethered electron-poor dienophiles more rapidly and in higher yield than non-nitrated furans. Computational studies indicate that increased stabilization of a partial positive charge on the nitro-substituted carbon in both transition state and product is the driving force for these reactions. Frontier molecular orbital energy differences
established that a cyclopentadienyl RhIII complex with two phenyl groups and a pendant amide moiety catalyzes the formal Lossen rearrangement/[3+2] annulation cascade of N‐pivaloyl benzamides and acrylamides with alkynes leading to substituted indoles and pyrroles. Mechanistic studies revealed that this cascade reaction proceeds via not the Lossen rearrangement to form anilides or enamides but C−H bond cleavage