Lewis Base Catalyzed Enantioselective Allylic Hydroxylation of Morita–Baylis–Hillman Carbonates with Water
摘要:
A Lewis base catalyzed allylic hydroxylation of Morita-Baylis-Hillman (MBH) carbonates has been developed. Various chiral MBH alcohols can be synthesized in high yields (up to 99%) and excellent enantioselectivities (up to 94% ee). This is the first report using water as a nucleophile in asymmetric organocatalysis. The nucleophilic role of water has been verified using O-18-labeling experiments.
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。
Catalyst‐Controlled Regiodivergent Synthesis of α/β‐Dipeptide Derivatives via
<i>N</i>
‐Allylic Alkylation of
<i>O‐</i>
Alkyl Hydroxamates with MBH Carbonates
A catalyst-controlled switchable N-allylic reaction of O-alkyl hydroxamates with MBH carbonates is reported, providing a regiodivergent method for α/β-dipeptides derivatives.
obtain optically active β-lactams, including the building block of the cholesterol-lowering drug Ezetimibe. An organocatalytic asymmetricallylicamination of Morita–Baylis–Hillman carbonates with aromatic amines in the presence of β-isocupreidine is described. Chiralallylic amines were obtained in almost quantitative yields (90–96%) with moderate enantioselectivity. Recrystallization afforded products
The first asymmetricorganocatalyticallylicalkylation of 1,2-dihydro-Reissert compounds and Morita–Baylis–Hillman (MBH) carbonates has been developed, which provided a novel protocol to construct enantioenriched functionalized 1,2-dihydroisoquinolines bearing vicinal quaternary and tertiary chiral centers at C-1 position (up to 94% ee, dr > 20 : 1).
The highly enantioselective asymmetric allylic alkylation of Morita–Baylis–Hillmancarbonates with bis(phenylsulfonyl)methane is presented. The reaction is simply catalyzed by cinchonaalkaloid derivatives affording the final alkylated products in good yields and enantioselectivities.
Acylation of Baylis-Hillman carbonates by visible light catalysis has been reported. Acyl radical is produced by decarboxylation of α-keto acid. This method has mild conditions, wide substrate scope, good functional group tolerance, and moderate to good yield, which provides a new route for the acylation of Baylis-Hillman derivatives.