13379-98-1Relevant academic research and scientific papers
Enantioselective syntheses of heteroyohimbine natural products: A unified approach through cooperative catalysis
Younai, Ashkaan,Zeng, Bi-Shun,Meltzer, Herbert Y.,Scheidt, Karl A.
, p. 6900 - 6904 (2015)
Alstonine and serpentine are pentacyclic indoloquinolizidine alkaloids (referred to as "anhydronium bases") containing three contiguous stereocenters. Each possesses interesting biological activity, with alstonine being the major component of a plant-based remedy to treat psychosis and other nervous system disorders. This work describes the enantioselective total syntheses of these natural products with a cooperative hydrogen bonding/enamine-catalyzed Michael addition as the key step. The enantioselective total syntheses of the natural products alstonine and serpentine are presented. They proceed through a sequence with a cooperative hydrogen bonding/enamine-catalyzed Michael addition as the key step.
Phosphine-Catalyzed Synthesis of Chiral N-Heterocycles through (Asymmetric) P(III)/P(V) Redox Cycling
Lorton, Charlotte,Saleh, Nidal,Voituriez, Arnaud
supporting information, p. 3340 - 3344 (2021/06/26)
Phosphine-catalyzed tandem Michael addition/intramolecular Wittig reactions have been developed for the synthesis of chiral 2,5-dihydro-1H-pyrrole and tetrahydropyridine derivatives. These processes have been rendered catalytic in phosphine, thanks to the in situ reduction of phosphine oxide by phenylsilane. Furthermore, catalytic and asymmetric P(III)/P(V) processes were implemented using enantiopure chiral phosphines.
Lewis Acid Catalyzed Electrophilic Aminomethyloxygenative Cyclization of Alkynols with N, O-Aminals
Chen, Anrong,Yu, Houjian,Yan, Jiaqi,Huang, Hanmin
supporting information, p. 755 - 759 (2020/01/28)
Lewis acid enables the electrophilic carbooxygenative cyclization of alkynols with N,O-aminals. The new process proceeds efficiently under very mild conditions via a pathway that is opposite to classical carbo-metalation. These reactions exhibit broad substrate generality and functional group compatibility, leading to a wide variety of 5-8-membered oxacycles bearing diverse functional groups. The cyclization products can be elaborated via simple functional group transformations to generate synthetically useful oxacycles.
Ynamide Smiles Rearrangement Triggered by Visible-Light-Mediated Regioselective Ketyl-Ynamide Coupling: Rapid Access to Functionalized Indoles and Isoquinolines
Chen, Yang-Bo,Sun, Zhou,Wang, Ze-Shu,Ye, Long-Wu,Zhang, Hao-Wen,Zhu, Chunyin
supporting information, p. 3636 - 3644 (2020/03/06)
In the past decades, significant advances have been made on radical Smiles rearrangement. However, the eventually formed radical intermediates in these reactions are limited to the amidyl radical, except for the few examples initiated by a N-centered radical. Here, a novel and practical radical Smiles rearrangement triggered by photoredox-catalyzed regioselective ketyl-ynamide coupling is reported, which represents the first radical Smiles rearrangement of ynamides. This method enables facile access to a variety of valuable 2-benzhydrylindoles with broad substrate scope in generally good yields under mild reaction conditions. In addition, this chemistry can also be extended to the divergent synthesis of versatile 3-benzhydrylisoquinolines through a similar ketyl-ynamide coupling and radical Smiles rearrangement, followed by dehydrogenative oxidation. Moreover, such an ynamide Smiles rearrangement initiated by intermolecular photoredox catalysis via addition of external radical sources is also achieved. By control experiments, the reaction was shown to proceed via key ketyl radical and α-imino carbon radical intermediates.
Electrochemical synthesis of sulfonamides in a graphite powder macroelectrode
Galdino, Danilo,Menezes, Paulo H.,Navarro, Marcelo,Vicente, Dmistocles A.
supporting information, p. 5262 - 5266 (2020/09/17)
The electrochemical generation of sulfinyl radicals from commercially available and non-expensive sodium salts of sulfinic acids is described. Electrooxidation reactions were carried out in a graphite powder macroelectrode using an aqueous electrolyte and cavity cell. Further reaction with primary or secondary amines gave the corresponding sulfonamides, a unit present in several biologically active compounds and pharmaceuticals, in good yields.
Direct spirocyclization from keto-sulfonamides: An approach to azaspiro compounds
Beltran, Frédéric,Fabre, Indira,Ciofini, Ilaria,Miesch, Laurence
supporting information, p. 5042 - 5045 (2017/11/06)
Spontaneous spirocyclization of keto-sulfonamides via ynamides through a one-pot process is presented. Push-pull ynamides were obtained through Michael addition/elimination without Cu. The obtained azaspiro compounds are building blocks for indole alkaloids. Theoretical studies provide insights into the mechanism of the formal Conia-ene reaction.
ENANTIOSELECTIVE SYNTHESES OF HETEROYOHIMBINE NATURAL PRODUCT INTERMEDIATES
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Paragraph 00029; 00030, (2016/11/21)
Enantioselective syntheses of cis- and trans-bicyclic dihydropyran compounds, and other intermediates, en route to heteroyohimbine alkaloids.
Ynamide Carbopalladation: A Flexible Route to Mono-, Bi- and Tricyclic Azacycles
Campbell, Craig D.,Greenaway, Rebecca L.,Holton, Oliver T.,Walker, P. Ross,Chapman, Helen A.,Russell, C. Adam,Carr, Greg,Thomson, Amber L.,Anderson, Edward A.
supporting information, p. 12627 - 12639 (2015/09/01)
Bromoenynamides represent precursors to a diversity of azacycles by a cascade sequence of carbopalladation followed by cross-coupling/electrocyclization, or reduction processes. Full details of our investigations into intramolecular ynamide carbopalladation are disclosed, which include the first examples of carbopalladation/cross-coupling reactions using potassium organotrifluoroborate salts; and an understanding of factors influencing the success of these processes, including ring size, and the nature of the coupling partner. Additional mechanistic observations are reported, such as the isolation of triene intermediates for electrocyclization. A variety of hetero-Diels-Alder reactions using the product heterocycles are also described, which provide insight into Diels-Alder regioselectivity.
Synthesis of oxazolidin-2-ones and imidazolidin-2-ones directly from 1,3-diols or 3-amino alcohols using iodobenzene dichloride and sodium azide
He, Tian,Gao, Wen-Chao,Wang, Wei-Kun,Zhang, Chi
supporting information, p. 1113 - 1118 (2014/04/03)
A general and efficient method for the synthesis of oxazolidin-2-ones and imidazolidin-2-ones directly from 1,3-diols and 3-amino alcohols has been developed using the same reagent combination of iodobenzene dichloride (PhICl2) and sodium azide (NaN3).
