Enanatiopure β‐methyl‐γ‐monofluoromethyl alcohols were prepared from the allylic alkylation between fluorobis(phenylsulfonyl)methane with Morita–Baylis–Hillmancarbonates. The reaction was catalyzed by using the Cinchonaalkaloid derivative, (DHQD)2AQN. The origin of the stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly
dihydrobenzofuran units are frequently present in molecules with significant biological and pharmaceutical activities. Herein, we present the first enantioselective formal [4+1] annulation of Morita‐Baylis‐Hillman carbonates with o‐quinone methides (o‐QMs) catalyzed by a newly designed chiral phosphine catalyst. Under the mild and eco‐friendly conditions, a wide range of polysubstituted dihydrobenzofurans were
available Cinchonaalkaloid as catalyst, the asymmetric allylic alkylation of Morita-Baylis-Hillmancarbonates, with alpha-fluoro-beta-keto esters as nucleophiles, have been successfully developed. A series of important fluorinated adducts, with chiral quaternary carbon centres containing a fluorine atom, was achieved in good yields (up to 93%), with good to excellent enantioselectivities (up to 96%
Cinchona Alkaloid Catalyzed Regio- and Enantioselective Allylic Amination of Morita-Baylis-Hillman Carbonates with Isatins
作者:Mei-Xin Zhao、Ming-Xiao Chen、Wen-Hao Tang、Deng-Ke Wei、Tong-Lei Dai、Min Shi
DOI:10.1002/ejoc.201200376
日期:2012.7
An efficient enantioselectiveallylicamination of Morita–Baylis–Hillman (MBH) carbonates derived from methyl acrylate and aromatic aldehydes with isatins has been realized in the presence of commercially available cinchonaalkaloids. The allylicamination products were obtained in moderate-to-good yields (46–74 %) with moderate-to-good enantioselectivities (up to 89 % ee) under mild conditions. The
The first phosphine-catalyzed highly enantioselective [3 + 3] cycloaddition of Morita-Baylis-Hillman carbonates with C,N-cyclicazomethineimines is described. Using a spirocyclic chiral phosphine as the catalyst, a novel class of pharmaceutically interesting 4,6,7,11b-tetrahydro-1H-pyridazino[6,1-a]iso-quinoline derivatives were obtained in high yields with good to excellent diastereoselectivities