Total Synthesis and Structural Elucidation of Azaspiracid-1. Final Assignment and Total Synthesis of the Correct Structure of Azaspiracid-1
作者:K. C. Nicolaou、Theocharis V. Koftis、Stepan Vyskocil、Goran Petrovic、Wenjun Tang、Michael O. Frederick、David Y.-K. Chen、Yiwei Li、Taotao Ling、Yoichi M. A. Yamada
DOI:10.1021/ja054750q
日期:2006.3.1
strategy for the total synthesis of azaspiracid-1 featured a dithiane anion (C(21)-C(27) fragment) reacting with a pentafluorophenol ester (C(1)-C(20) fragment) followed by a Stille-type union of an advanced allylic acetate substrate (C(1)-C(27) fragment) with a vinyl stannane as the main coupling processes to assemble the carbon skeleton of the molecule. In addition to the total synthesis of azaspiracid-1
Regioselective Formal [3+2] Cycloadditions of Urea Substrates with Activated and Unactivated Olefins for Intermolecular Olefin Aminooxygenation
作者:Fan Wu、Nur‐E Alom、Jeewani P. Ariyarathna、Johannes Naß、Wei Li
DOI:10.1002/anie.201904662
日期:2019.8.19
A new class of intermolecular olefin aminooxygenation reaction is described. This reaction utilizes the classic halonium intermediate as a regio‐ and stereochemical template to accomplish the selective oxyamination of both activated and unactivated alkenes. Notably, urea chemical feedstock can be directly introduced as the N and O source and a simple iodide salt can be utilized as the catalyst. This
and other biologically active small molecules. Herein, we report their direct synthesis from alkenes through an aminative difunctionalization reaction enabled by iron catalysis. A family of ten novel hydroxylamine‐derived aminating reagents were designed for the installation of several medicinally relevant amine groups, such as methylamine, morpholine and piperazine, through the aminochlorination of
An Ir(ppy)3-catalyzed vic-diphosphination of styrenes with Me3Si-PPh2 and NFSI proceeds under blue LED irradiation to afford the corresponding bis(diphenylphosphino)ethane derivatives without any formation of hydrophosphination byproducts, which are inevitable and problematic under the previous Cu/NHC catalysis. Additionally, the visible-light-promoted photoredox catalysis enables the diphosphination
Me 3 Si-PPh 2和NFSI对苯乙烯进行Ir(ppy)3催化的维克二磷酸化,在蓝色LED辐射下进行,得到相应的双(二苯基膦基)乙烷衍生物,而没有形成任何磷酸化副产物,这在不可避免的情况下是有问题的先前的Cu / NHC催化。另外,可见光促进的光氧化还原催化能够使相对具有挑战性的脂族烯烃和β-取代的苯乙烯进行二磷酸化。
Total Synthesis and Structural Elucidation of Azaspiracid-1. Construction of Key Building Blocks for Originally Proposed Structure
作者:K. C. Nicolaou、Petri M. Pihko、Federico Bernal、Michael O. Frederick、Wenyuan Qian、Noriaki Uesaka、Nicole Diedrichs、Jürgen Hinrichs、Theocharis V. Koftis、Eriketi Loizidou、Goran Petrovic、Manuela Rodriquez、David Sarlah、Ning Zou
DOI:10.1021/ja0547477
日期:2006.2.1
required for the totalsynthesis of the proposedstructure of azaspiracid-1 (1a) are described. Key steps include a TMSOTf-induced ring-closing cascade to form the ABC rings of tetracycle 65, a neodymium-catalyzed internal aminal formation for the construction of intermediate 98, and a Nozaki-Hiyama-Kishi coupling to assemble the required carbon chain of fragment 100. The synthesized fragments, obtained stereoselectively