Asymmetric allylic amination of Morita–Baylis–Hillman (MBH) adducts with simple aromatic amines is successfully realized by nucleophilic amine catalysis. A range of substituted α-methylene-β-arylamino esters is accessed in moderate to high yields (up to 88%) and with excellent enantioselectivities (up to 97% ee). Inorganic fluorides are found to be able to improve the enantioselectivity of the allylic
Asymmetric allylicsubstitution of Morita–Baylis–Hillman (MBH) carbonates with less-nucleophilic phenols mediated by nucleophilic amine catalysis was successfully developed. A variety of substituted aryl allyl ethers were afforded with moderate to high yields with excellent enantioselectivities. The chiral MBH alcohol could be easily accessed from the corresponding aryl allyl ether.
The organocatalytic asymmetric allylic etherification reaction of Morita–Baylis–Hillmancarbonates and silanols was reported for the first time. With modified cinchonaalkaloid (DHQD)2PYR as the catalyst, a series of aromatic, heterocyclic, or aliphatic Morita–Baylis–Hillmancarbonates (25 examples) worked well with triphenylsilanol, affording the corresponding products in moderate to good yields (up
a cinchonine derived alkaloid, catalyzed asymmetric SN2′–SN2′ reaction between N-2,2,2-trifluoroethylisatin ketimines and MBH type carbonates was realized in a simple and efficient way. A series of chiral α-trifluoromethylamines were prepared with excellent yields and stereoselectivities. A subsequent and easy process of deprotection gave γ-trifluoromethyl-α-methylenelactam in a stereoselective manner
通过简单有效的方法,实现了由辛可宁衍生的生物碱β-异cupreidine催化的N -2,2,2-三氟乙基异丁酮酮与MBH型碳酸盐之间的不对称S N 2'–S N 2'反应。制备了一系列具有优异收率和立体选择性的手性α-三氟甲基胺。随后且容易的脱保护过程以立体选择性的方式得到了γ-三氟甲基-α-亚甲基内酰胺。
Phosphine-Catalyzed [3 + 2] Annulation of Morita–Baylis–Hillman Carbonates with Isoxazole-Based Alkenes
A phosphine-catalyzed [3 + 2] annulation of Morita–Baylis–Hillman (MBH) carbonates with 3-methyl-4-nitro-5-styrylisoxazoles has been developed to afford various multifunctional isoxazoles in moderate to good yields with moderate to excellent diastereoselectivities. With a spirocyclic chiral phosphine as the catalyst, up to 89% ee was obtained.