scholarly journals Synthesis of New Functionally Substituted 9-Azabicyclo[4.2.1]nona-2,4,7-Trienes by Cobalt(I)-Catalyzed [6π + 2π]-Cycloaddition of N-Carbocholesteroxyazepine to Alkynes

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2932
Author(s):  
Gulnara N. Kadikova ◽  
Vladimir A. D’yakonov ◽  
Usein M. Dzhemilev
Keyword(s):  
Catalytic System ◽  
Nmr Spectra ◽  
Two Dimensional ◽  
Terminal Alkynes ◽  
First Time ◽  
Natural Metabolite ◽  
Covalently Bound

Catalytic [6π + 2π]-cycloaddition of N-carbocholesteroxyazepine with functionally substituted terminal alkynes and 1,4-butynediol was performed for the first time under the action of the Co(acac)2(dppe)/Zn/ZnI2 three-component catalytic system. The reaction gave previously undescribed but promising 9-azabicyclo[4.2.1]nona-2,4,7-trienes (in 79–95% yields), covalently bound to a natural metabolite, cholesterol. The structure of the synthesized azabicycles was confirmed by analysis of one- and two-dimensional (1H, 13C, DEPT 13C, COSY, NOESY, HSQC, HMBC) NMR spectra.

scholarly journals Five sesquiterpenes from the root Aucklandia lappa Decne.

2019 ◽  
pp. 5-11
Author(s):  
Chjuo Fuguan ◽  
Seesregdorj S ◽  
Gerelt-Od Ya
Keyword(s):  
Phenolic Compounds ◽  
Nmr Spectra ◽  
Previous Literature ◽  
Two Dimensional ◽  
Nmr Data ◽  
Nmr Techniques ◽  
The One ◽  
Dehydrocostus Lactone ◽  
First Time

The four sesquiterpenes calameone (1), dehydrocostus lactone (2), aristolone (3), alantolactone (4) and one triterpenoid α-amyrine (5), simple phenolic compounds such as 4-hydroxybenzaldehyde, (6), piceol (7), apocynin (8), dihydroconiferyl (9) and coniferyl (10) have been identified by using the proton and carbon NMR spectra which were isolated from a dichloromethane extract of the roots of Aucklandia lappa Decne. Their structures were established by the one‐and two‐dimensional NMR techniques including DEPT, COSY and HMBC spectroscopy. This work examined proton and carbon NMR data of calameone (1) and aristolone (3) for the first time, which had not yet been fully studied in previous literature. Рүда ургамлын (Aucklandia lappa Decne.) терпент нэгдлийн судалгаа Хураангуй: Рүда ургамлын үндэсний дихлорметаны ханднаас хроматографийн аргуудаар эвдесман хэлбэрийн сесквитерпен каламеон (1), аристолон (3), алантолактон (4), гвяан хэлбэрийн сесквитерпен дегидрокостасын лактон (2), тритерпеноид α-амурин (5) болон энгийн фенолт нэгдэл 4-гидроксибензальдегид (6), пицелол (7), апоцинин (8), дегидрокониферол (9), кониферол (10) зэрэг бодисыг химийн цэвэр байдалтай ялгав. Эдгээр бодисын бүтэц байгуулалтыг нэг болон хоёр хэмжээст ЦСР-ын DEPT, COSY, HMBC спектроскопийн аргаар таньж тодорхойлов. Урьд өмнө каламеон (1), аристолон (3) бодисуудын устөрөгч ба нүүрстөрөгчийн атомуудын химийн шилжилтийн утгуудад оноолт бүрэн хийгдээгүй байсан ба энэ хоёр бодисын оноолтыг гүйцээж хийв. Түлхүүр үг: Терпеноид, сесквитерпент лактон, дегидрокостасын лактон, ЦСР.

Determination of Coupling Signs 1J(119Sn, 15N ) and 2J(119Sn, 117Sn) in Trimethylstannylamines

1998 ◽  
Vol 53 (12) ◽  
pp. 1494-1500 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Jürgen Weidinger ◽  
Heinrich Nöth ◽  
Wolfgang Storch ◽  
Thomas Seifert ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Lone Pair ◽  
Coupling Constants ◽  
Positive Sign ◽  
Two Dimensional ◽  
Ultrahigh Resolution ◽  
Sign Inversion ◽  
First Time ◽  
Influence Of Substituents

The l5N-labelled trimethylstannylamines 1 - 3 [(Me3Sn)3N, (Me3Sn)2NPh, (Me3Sn)2NBCgHi4 (BCgHi4 = 9-borabicyclo[3.3.0]nonyn and the non-labelled 4, Me3Sn-N(BC8Hi4)2 , were prepared and studied by 1H, 1C, 15N and 119Sn NMR. The 15N ultrahigh resolution NMR spectra of 1 revealed otherwise unobserved parameters such as 2J(15N ,Sn ,13C ) and the isotope induced chemical shift 2Δ12/13C(15N). 119Sn NMR spectra of 1, recorded under similar conditions, also show new parameters such as 3J(119Sn,N,Sn,13C) which are not resolved in the non-labelled derivative. By using various types o f two-dimensional heteronuclear shift correlations, absolute coupling signs of 1J(119Sn,15N) (all < 0) in 1 - 3 were determined. By the same techniques it proved possible to confirm the negative sign o f :7(Sn,Sn) (-195.4 Hz) in 1. In contrast, the coupling constants 2J(Sn,Sn) for 2 (+71.7) and 3 (+62.0) possess a positive sign. This sign inversion, observed here for the first time for apparently similar compounds, demonstrates the enormous influence of substituents on the nature of the lone pair of electrons at the nitrogen atom. It also shows that these experiments for sign determinations of coupling constants are necessary in order to interpret these data correctly.

Ni-Catalyzed regio- and stereoselective addition of arylboronic acids to terminal alkynes with a directing group tether

2017 ◽  
Vol 53 (27) ◽  
pp. 3894-3897 ◽  
Author(s):  
Madala Hari Babu ◽  
Gadi Ranjith Kumar ◽  
Ruchir Kant ◽  
Maddi Sridhar Reddy
Keyword(s):  
Catalytic System ◽  
Terminal Alkynes ◽  
Arylboronic Acids ◽  
Stereoselective Addition ◽  
Directing Group ◽  
First Time ◽  
P Addition

Addition of arylboronic acids to directing group tethered acetylenes in a regio and stereoselective manner using an inexpensive catalytic system is achieved for the first time to access highly sought after allyl/homoallyl alcohol/amine units.

Cobalt/Lewis Acid Catalysis for Hydrocarbofunctionalization of Alkynes via Cooperative C–H Activation

2020 ◽  
Author(s):  
Chang-Sheng Wang ◽  
Sabrina Monaco ◽  
Anh Ngoc Thai ◽  
Md. Shafiqur Rahman ◽  
Chen Wang ◽  
...  
Keyword(s):  
Catalytic System ◽  
Lewis Acid ◽  
Hydrogen Transfer ◽  
Acid Catalysis ◽  
Rate Limiting Step ◽  
Site Selectivity ◽  
Set Up ◽  
Site Selective ◽  
First Time ◽  
Rate Limiting

A catalytic system comprised of a cobalt-diphosphine complex and a Lewis acid (LA) such as AlMe3 has been found to promote hydrocarbofunctionalization reactions of alkynes with Lewis basic and electron-deficient substrates such as formamides, pyridones, pyridines, and azole derivatives through site-selective C-H activation. Compared with known Ni/LA catalytic system for analogous transformations, the present catalytic system not only feature convenient set up using inexpensive and bench-stable precatalyst and ligand such as Co(acac)3 and 1,3-bis(diphenylphosphino)propane (dppp), but also display distinct site-selectivity toward C-H activation of pyridone and pyridine derivatives. In particular, a completely C4-selective alkenylation of pyridine has been achieved for the first time. Mechanistic stidies including DFT calculations on the Co/Al-catalyzed addition of formamide to alkyne have suggested that the reaction involves cleavage of the carbamoyl C-H bond as the rate-limiting step, which proceeds through a ligand-to-ligand hydrogen transfer (LLHT) mechanism leading to an alkyl(carbamoyl)cobalt intermediate.

scholarly journals Influence of a Standing Wave Flow-Field on the Dynamics of a Spray Diffusion Flame

Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
J. Barry Greenberg ◽  
David Katoshevski
Keyword(s):  
Liquid Phase ◽  
Flow Field ◽  
Standing Wave ◽  
Diffusion Flame ◽  
Stokes Number ◽  
Flame Height ◽  
Wave Flow ◽  
Two Dimensional ◽  
Governing Equations ◽  
First Time

A theoretical investigation of the influence of a standing wave flow-field on the dynamics of a laminar two-dimensional spray diffusion flame is presented for the first time. The mathematical analysis permits mild slip between the droplets and their host surroundings. For the liquid phase, the use of a small Stokes number as the perturbation parameater enables a solution of the governing equations to be developed. Influence of the standing wave flow-field on droplet grouping is described by a specially constructed modification of the vaporization Damkohler number. Instantaneous flame front shapes are found via a solution for the usual Schwab–Zeldovitch parameter. Numerical results obtained from the analytical solution uncover the strong bearing that droplet grouping, induced by the standing wave flow-field, can have on flame height, shape, and type (over- or under-ventilated) and on the existence of multiple flame fronts.

scholarly journals Tetrazine molecules as efficient electronic diversion channel in 2D organic-inorganic perovskites

2021 ◽  
Author(s):  
Ferdinand Lédée ◽  
Pierre Audebert ◽  
Gaëlle Trippé-Allard ◽  
Laurent Galmiche ◽  
Damien Garrot ◽  
...  
Keyword(s):  
Organic Component ◽  
Two Dimensional ◽  
Diversion Channel ◽  
Halide Perovskites ◽  
First Time

We present the synthesis of two novel two-dimensional (2D) hybrid organic-inorganic halide perovskites incorporating for the first time 100% of a photoactive tetrazine derivative as the organic component. With this...

scholarly journals Exfoliation in a low boiling point solvent and electrochemical applications of MoO3

2020 ◽  
Vol 11 ◽  
pp. 662-670
Author(s):  
Matangi Sricharan ◽  
Bikesh Gupta ◽  
Sreejesh Moolayadukkam ◽  
H S S Ramakrishna Matte
Keyword(s):  
Energy Storage ◽  
Electrode Material ◽  
Electronic Devices ◽  
High Specific Capacitance ◽  
Two Dimensional ◽  
Energy Storage Devices ◽  
Intrinsic Nature ◽  
Storage Devices ◽  
Scan Rate ◽  
First Time

MoO3 is a versatile two-dimensional transition metal oxide having applications in areas such as energy storage devices, electronic devices and catalysis. To efficiently utilize the properties of MoO3 arising from its two-dimensional nature exfoliation is necessary. In this work, the exfoliation of MoO3 is carried out in 2-butanone for the first time. The achieved concentration of the dispersion is about 0.57 mg·mL−1 with a yield of 5.7%, which are the highest values reported to date. These high values of concentration and yield can be attributed to a favorable matching of energies involved in exfoliation and stabilization of MoO3 nanosheets in 2-butanone. Interestingly, the MoO3 dispersion in 2-butanone retains its intrinsic nature even after exposure to sunlight for 24 h. The composites of MoO3 nanosheets were used as an electrode material for supercapacitors and showed a high specific capacitance of 201 F·g−1 in a three-electrode configuration at a scan rate of 50 mV·s−1.

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