CO<sub>2</sub>-Activation for γ-Butyrolactones and Its Application in the Total Synthesis of (±)-Heteroplexisolide E
作者:Suhua Li、Shengming Ma
DOI:10.1002/asia.201200467
日期:2012.10
is described. The catalyst is highly active and can be applied for the synthesis of (optically active) mono‐ or bicyclic α‐alkylidene‐γ‐butyrolactones with excellent regio‐ and stereoselectivity and good functional group tolerance. The potential of the reaction has been demonstrated in the first synthesis of (±)‐heteroplexisolide E.
and nickel catalysts, furnishing five-membered cyclic boryl ethers regioselectively in good yields via 5-exo cyclization. The products were transformed into highly substitutedα,β-unsaturatednitriles via Suzuki–Miyaura coupling to aryl iodides, rhodium-catalyzed conjugative addition to methyl vinyl ketone, and rhodium-catalyzed protodeborylation.
Intramolecularaddition of a boron-cyano bond across a carbon-carbontriple bond was achieved using palladium and nickel catalysts. Cyano(diisopropylamino)boryl homopropargyl ethers underwent regio- and stereoselective 5-exo cyclization, forming five-membered cyclic boryl ethers in high yields. The cyanoboration products thus obtained served as new precursors for the synthesis of highly substituted
Highly Selective Nickel-Catalyzed Methyl-Carboxylation of Homopropargylic Alcohols for α-Alkylidene-γ-butyrolactones
作者:Suhua Li、Shengming Ma
DOI:10.1021/ol202520x
日期:2011.11.18
A first practical Ni(0)-catalyzed highly stereoselective methyl-carboxylation of homopropargylic alcohols with ZnMe2 and CO2 for the efficient synthesis of alpha-alkylidene-gamma-butyrolactones is described. The reaction may be applied to other alkynols.
Inghan,C.F. et al., Australian Journal of Chemistry, 1974, vol. 27, p. 1477 - 1489