大多数天然存在的吲哚二萜共享6/5/5/6/6/6六环系统,而偶尔观察到6/8/6/6/6五环骨架。在这项研究中,我们证明了通过非酶黄素催化氧化吲哚开环形成八元C-N杂环。更有趣的是, 18个O标记实验证明,掺入的两个氧原子主要来自水而不是分子氧。在此过程中,黄素的氧化形式催化胺到亚胺的两次连续氧化,并涉及环扩展的水解。然后还原的黄素通过用分子氧氧化形成H 2 O 2来再生。
Asymmetric Total Synthesis of the Indole Diterpene Alkaloid Paspaline
作者:Robert J. Sharpe、Jeffrey S. Johnson
DOI:10.1021/acs.joc.5b01844
日期:2015.10.2
An enantioselective synthesis of the indole diterpenoid natural product paspaline is disclosed. Critical to this approach was the implementation of stereoselective desymmetrization reactions to assemble key stereocenters of the molecule. The design and execution of these tactics are described in detail, and a thorough analysis of observed outcomes is presented, ultimately providing the title compound
A Global and Local Desymmetrization Approach to the Synthesis of Steroidal Alkaloids: Stereocontrolled Total Synthesis of Paspaline
作者:Robert J. Sharpe、Jeffrey S. Johnson
DOI:10.1021/jacs.5b02631
日期:2015.4.22
A stereocontrolled totalsynthesis of the indole diterpenoid natural product paspaline is described. Key steps include a highly diastereoselective enzymatic desymmetrization, substrate-directed epoxidation, Ireland-Claisen rearrangement, and diastereotopic group selective C-H acetoxylation to assemble the target with excellent stereofidelity. The route and results described herein outline complementary
Nodulisporic acid E biosynthesis: <i>in vivo</i> characterisation of NodD1, an indole-diterpene prenyltransferase that acts on an emindole SB derived indole-diterpene scaffold
作者:Kyle C. Van de Bittner、Rosannah C. Cameron、Leyla Y. Bustamante、Rudranuj Bundela、Sarah A. Kessans、Jan Vorster、Matthew J. Nicholson、Emily J. Parker
DOI:10.1039/c9md00143c
日期:——
Prenylation of aromatic compounds is a key tailoring reaction in biosynthesis of bioactive indole-diterpenes. Here, we identify NodD1 as the enzyme responsible for the bisprenylation of nodulisporic acid F. This prenyltransferase showed a preference for its natural indole-diterpene substrate whereas other related enzymes were not able to catalyse this conversion.
芳香族化合物的异戊二烯化是生物活性吲哚二萜生物合成中的关键定制反应。在这里,我们将 NodD1 确定为负责球孢酸 F 双异戊二烯化的酶。这种异戊烯基转移酶显示出对其天然吲哚二萜底物的偏好,而其他相关酶无法催化这种转化。
Indole diterpene synthetic studies. 2. First-generation total synthesis of (-)-paspaline
作者:Richard E. Mewshaw、Michael D. Taylor、Amos B. Smith
DOI:10.1021/jo00275a035
日期:1989.7
Total Synthesis of Paspaline A and Emindole PB Enabled by Computational Augmentation of a Transform-Guided Retrosynthetic Strategy
作者:Daria E. Kim、Joshua E. Zweig、Timothy R. Newhouse
DOI:10.1021/jacs.8b13127
日期:2019.1.30
We report the total syntheses of two indole diterpenoid natural products, paspaline A and emindole PB. Paspaline A is synthesized in a 9-step sequence from commercially available materials. The first total synthesis of emindole PB is accomplished in 13 steps and confirms a previously ambiguous structural assignment. Density functional theory calculations are utilized to interrogate the key carbocationic rearrangement in a predictive capacity to aid in the selection of the most favorable precursor substrate. This work highlights how retro-synthetic design can be augmented with quantum chemical calculations to reveal energetically feasible synthetic disconnections, minimizing time-consuming and expensive empirical evaluation.