本文描述了(邻叠氮基芳基)丙二酸酯的催化不对称施陶丁格-氮杂-维蒂希反应,允许通过氧化膦催化获得手性季羟吲哚。我们设计了一种新型 HypPhos 氧化物催化剂,可在硅烷还原剂和 Ir I基路易斯酸存在下通过 P III /P V =O 氧化还原循环实现去对称 Staudinger-aza-Wittig 反应。该反应条件温和,官能团耐受性好,底物范围广,具有优异的对映选择性。密度泛函理论表明,去对称反应中的对映选择性源于 Ir I物种和 HypPhos 催化剂的协同作用。该方法的实用性通过七种生物碱靶标的(正式)合成得到证明:(−)-胶粘蛋白 C、(−)-coerulescine、(−)-horsfiline、(+)-deoxyeseroline、(+)-esermethole、( +)-毒扁豆碱和(+)-毒扁豆碱。
Diastereoselective Nitrenium Ion-Mediated Cyclofunctionalization: Total Synthesis of (+)-Castanospermine
摘要:
The asymmetric total synthesis of the cc-glucosidase inhibitor (+)-castanospermine is reported. The central theme in our approach to this polyhydroxylated alkaloid is the simultaneous generation of the piperidine ring and the C-1/8a erythro stereodiad through the diastereoselective, oxamidation of an unsaturated O-alkyl hydroxamate. This process is believed to proceed sequentially via singlet acylnitrenium and aziridinium ion intermediates.
Herein, we report the synthetically practical, short, and general access to novel indolophane architectures by means of a photochemical C−H activation process—the Witkop cyclization. These highly strained scaffolds were obtained by photoinduced ring closure and feature atropisomerism as well as aromatic ring current effects, which both have been investigated. The prevailing regioselectivity of theWitkop
Enantioselective Synthesis of Cyclohepta[<i>b</i>]indoles: Gram-Scale Synthesis of (<i>S</i>)-SIRT1-Inhibitor IV
作者:Philipp J. Gritsch、Erik Stempel、Tanja Gaich
DOI:10.1021/ol4026217
日期:2013.11
An enantioselective gram-scale synthesis of one of the most potent SIRT1-inhibitors has been accomplished by an unprecedented domino reaction sequence establishing the cyclohepta[b]indole core. This method was developed for application in natural product synthesis of a variety of indole alkaloids.
Diastereoselective Nitrenium Ion-Mediated Cyclofunctionalization: Total Synthesis of (+)-Castanospermine
作者:Edward G. Bowen、Duncan J. Wardrop
DOI:10.1021/ol102371x
日期:2010.11.19
The asymmetric total synthesis of the cc-glucosidase inhibitor (+)-castanospermine is reported. The central theme in our approach to this polyhydroxylated alkaloid is the simultaneous generation of the piperidine ring and the C-1/8a erythro stereodiad through the diastereoselective, oxamidation of an unsaturated O-alkyl hydroxamate. This process is believed to proceed sequentially via singlet acylnitrenium and aziridinium ion intermediates.
Enantioselective Synthesis of Quaternary Oxindoles: Desymmetrizing Staudinger–Aza-Wittig Reaction Enabled by a Bespoke HypPhos Oxide Catalyst
asymmetric Staudinger–aza-Wittig reaction of (o-azidoaryl)malonates, allowing access to chiral quaternary oxindoles through phosphine oxide catalysis. We designed a novel HypPhos oxide catalyst to enable the desymmetrizing Staudinger–aza-Wittig reaction through the PIII/PV═O redox cycle in the presence of a silane reductant and an IrI-based Lewis acid. The reaction occurs under mild conditions, with
本文描述了(邻叠氮基芳基)丙二酸酯的催化不对称施陶丁格-氮杂-维蒂希反应,允许通过氧化膦催化获得手性季羟吲哚。我们设计了一种新型 HypPhos 氧化物催化剂,可在硅烷还原剂和 Ir I基路易斯酸存在下通过 P III /P V =O 氧化还原循环实现去对称 Staudinger-aza-Wittig 反应。该反应条件温和,官能团耐受性好,底物范围广,具有优异的对映选择性。密度泛函理论表明,去对称反应中的对映选择性源于 Ir I物种和 HypPhos 催化剂的协同作用。该方法的实用性通过七种生物碱靶标的(正式)合成得到证明:(−)-胶粘蛋白 C、(−)-coerulescine、(−)-horsfiline、(+)-deoxyeseroline、(+)-esermethole、( +)-毒扁豆碱和(+)-毒扁豆碱。