使用顺磁性钴(II)卟啉催化剂[Co II (TPP)](TPP=四苯基卟啉)对邻烯丙基羰基-芳基N-芳基磺酰腙进行金属自由基活化,为合成新型8元杂环化合物提供了一种有效且强大的方法烯醇醚。该合成方案通用且实用,能够以高产率合成多种独特的 1 H -2-苯并氧辛。催化环化反应具有优异的化学选择性,具有较高的官能团耐受性,并为合成新的生物活性化合物提供了多种机会。该反应通过钴(III)-卡宾自由基中间体进行,该中间体参与从烯丙基位置到卡宾自由基的分子内氢转移(HAT),然后在钴的配位层中进行近无障碍的自由基反弹步骤。所提出的机制得到了实验观察、密度泛函理论(DFT)计算和自旋捕获实验的支持。
使用顺磁性钴(II)卟啉催化剂[Co II (TPP)](TPP=四苯基卟啉)对邻烯丙基羰基-芳基N-芳基磺酰腙进行金属自由基活化,为合成新型8元杂环化合物提供了一种有效且强大的方法烯醇醚。该合成方案通用且实用,能够以高产率合成多种独特的 1 H -2-苯并氧辛。催化环化反应具有优异的化学选择性,具有较高的官能团耐受性,并为合成新的生物活性化合物提供了多种机会。该反应通过钴(III)-卡宾自由基中间体进行,该中间体参与从烯丙基位置到卡宾自由基的分子内氢转移(HAT),然后在钴的配位层中进行近无障碍的自由基反弹步骤。所提出的机制得到了实验观察、密度泛函理论(DFT)计算和自旋捕获实验的支持。
The enantioselectiveintermolecular cross Rauhut-Currierreaction of acrolein with active olefins has been a long-standing challenge because of competitive MBH reaction and polymerization. Reported herein is a highly enantioselectiveintermolecular...
A TMG catalyzed, practical and efficient hydrophosphorylation of 4-oxo-enoates by diethyl or diphenyl phosphite has been described. This protocol allows a convenient access to a variety of enol phosphates under mild conditions in good yield with excellent stereoselectivity.
Cooperative Heterobimetallic Zinc/Alkaline Earth Metal Catalysis: A Zn/Sr Aminophenol Sulfonamide Complex for Catalytic Asymmetric Michael Addition of 3-Acetoxy-2-oxindoles to β-Ester Enones
A heterobimetallic zinc/strontium catalyst has been developed for the asymmetric Michael addition of 3-acetoxy-2-oxindoles to β-ester enones in high yields with excellent enantioselectivities and high diastereoselectivities. This process represents that 3-acetoxy-2-oxindoles can be used as a stable air- and base-tolerant precursor for chiral 3-substituted 3-hydroxy-2-oxindoles.
Highly Enantioselective Intermolecular Cross Rauhut-Currier Reaction Catalyzed by a Multifunctional Lewis Base Catalyst
作者:Xuelin Dong、Ling Liang、Erqing Li、You Huang
DOI:10.1002/anie.201409744
日期:2015.1.26
The highlyenantioselective intermolecular cross Rauhut–Currier reaction of different active olefins catalyzed by a multifunctional chiral Lewisbase was reported. The RC products were obtained in excellent yields (up to 98 %), high chemo‐ and enantioselectivity (up to 96 % ee). The reaction could be performed on a gram scale using 1 mol % of the multifunctional phosphine catalyst.
Organocatalytic Enantioselective Direct Vinylogous Michael Addition of γ-Substituted Butenolides to 3-Aroyl Acrylates and 1,2-Diaroylethylenes
作者:Utpal Das、Yi-Ru Chen、Yi-Ling Tsai、Wenwei Lin
DOI:10.1002/chem.201301332
日期:2013.6.10
Adding value: The directvinylogousMichaeladdition of γ‐substituted butenolides with a series of 3‐aroyl acrylates and 1,2‐diaroylethylenes has been demonstrated. This organocatalytic method delivers highly enantio‐ and diastereomerically pure γ,γ‐disubstituted butenolides with adjacent quaternary and tertiary stereocenters (see scheme).