Theoretical characterization of first and second generation Grubbs catalysts in styrene cross-metathesis reactions: insights from conceptual DFT

2016 ◽  
Vol 6 (3) ◽  
pp. 755-766 ◽  
Author(s):  
Katherine Paredes-Gil ◽  
Pablo Jaque
Keyword(s):  
Second Generation ◽  
Reorganization Energy ◽  
Conceptual Dft ◽  
Reactivity Descriptors ◽  
Cross Metathesis ◽  
Grubbs Catalysts ◽  
Metathesis Reactions ◽  
Theoretical Characterization ◽  
First And Second Generation

Reorganization energy and DFT-based reactivity descriptors revealed important issues regarding the performance of Grubbs catalysts.

Alkene Metathesis: Synthesis of Panaxytriol (Lee), Isofagomine (Imahori and Takahata), Elatol (Stoltz), 5-F2t -Isoprostane (Snapper), and Ottelione B (Clive)

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Grignard Reagent ◽  
Conjugate Addition ◽  
Ring Closing Metathesis ◽  
University Of Illinois ◽  
Enantiomerically Pure ◽  
University Of Alberta ◽  
Cross Metathesis ◽  
Grubbs Catalysts ◽  
The University ◽  
First And Second Generation

Alkene metathesis has been used to prepare more and more challenging natural products. The first and second generation Grubbs catalysts 1 and 2 and the Hoveyda catalyst 3 are the most widely used. Daesung Lee of the University of Illinois at Chicago designed (Organic Lett. 2008, 10, 257) a clever chain-walking cross metathesis, combining 4 and 5 to make 6. The diyne 3 was carried on (3R, 9R, 10R )-Panaxytriol 7. Tatsushi Imahori and Hiroki Takahata of Tohoku Pharmaceutical University found (Tetrahedron Lett. 2008, 49, 265) that of the several derivatives investigated, the unprotected alcohol 8 cyclized most efficiently. Selective cleavage of the monosubstituted alkene followed by hydroboration delivered the alkaloid Isofagomine 10. Brian M. Stoltz of Caltech established (J. Am. Chem. Soc. 2008 , 130 , 810) the absolute configuration of the halogenated chamigrene Elatol 14 using the enantioselective enolate allylation that he had previously devised. A key feature of this synthesis was the stereocontrolled preparation of the cis bromohydrin. Marc L. Snapper of Boston College opened (J. Org. Chem. 2008, 73, 3754) the strained cyclobutene 15 with ethylene to give the diene 16. Remarkably, cross metathesis with 17 delivered 18 with high regioselectivity, setting the stage for the preparation of the 5-F2t - Isoprostane 19. Derrick L. J. Clive of the University of Alberta assembled (J. Org. Chem. 2008, 73, 3078) Ottelione B 26 from the enantiomerically-pure aldehyde 20. Conjugate addition of the Grignard reagent 21 derived from chloroprene gave the kinetic product 22, that was equilibrated to the more stable 23. Addition of vinyl Grignard followed by selective ring-closing metathesis then led to 26.

Synthesis of α,β-unsaturated aldehydes and nitriles via cross-metathesis reactions using Grubbs’ catalysts

2014 ◽  
Vol 486 ◽  
pp. 94-104 ◽  
Author(s):  
Sandra M. Rountree ◽  
Sarah F.R. Taylor ◽  
Christopher Hardacre ◽  
M. Cristina Lagunas ◽  
Paul N. Davey
Keyword(s):  
Cross Metathesis ◽  
Unsaturated Aldehydes ◽  
Grubbs Catalysts ◽  
Metathesis Reactions

scholarly journals A facile route for rubber breakdown via cross metathesis reactions

2016 ◽  
Vol 18 (11) ◽  
pp. 3448-3455 ◽  
Author(s):  
R. F. Smith ◽  
S. C. Boothroyd ◽  
R. L. Thompson ◽  
E. Khosravi
Keyword(s):  
Double Bonds ◽  
Cross Metathesis ◽  
Grubbs Catalysts ◽  
Metathesis Reactions ◽  
Facile Route

Cross-linked rubbery networks can be broken down using Grubbs catalysts by cross-metathesis reactions with backbone double bonds.

scholarly journals C-Glycosidic Genistein Conjugates and Their Antiproliferative Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Aleksandra Rusin ◽  
Maciej Chrubasik ◽  
Katarzyna Papaj ◽  
Grzegorz Grynkiewicz ◽  
Wiesław Szeja
Keyword(s):  
Cell Cycle ◽  
Culture Medium ◽  
Parent Compound ◽  
Metathesis Reaction ◽  
Cross Metathesis ◽  
Grubbs Catalysts ◽  
M Phase ◽  
First And Second Generation ◽  
Antiproliferative Activities

This paper presents our attempt to investigate scopes and the limitations of olefin cross-metathesis (CM) reaction in the synthesis of complex C-glycosides of genistein and evaluation of their antiproliferative activities. Novel genistein glycoconjugates were synthesized with the utility of CM reaction initiated by first and second generation of Grubbs catalysts. The relative reactivity of utilized olefins, based on categories proposed by Grubbs, was estimated.In vitroexperiments in cancer cell lines showed that the selected derivatives (3aand3f) exhibited higher antiproliferative potential than the parent compound, genistein, and were able to block the cell cycle in the G2/M phase. The observed mechanism of action of C-glycosidic derivatives was similar to the activity of their O-glycosidic counterparts. These compounds were stable in culture medium. The obtained results show that our approach to genistein modification with application of cross-metathesis reaction allowed to obtain stable glycoconjugates with improved anticancer potential, compared to the parent isoflavone.

Characterization of Electrical Reconnection Following Pulmonary Vein Isolation Using First- and Second-Generation Cryoballoon

2016 ◽  
Vol 39 (5) ◽  
pp. 434-442 ◽  
Author(s):  
BUELENT KOEKTUERK ◽  
HIKMET YORGUN ◽  
OEZLEM KOEKTUERK ◽  
CEM H. TURAN ◽  
KERIM KESKIN ◽  
...  
Keyword(s):  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Second Generation ◽  
First And Second Generation
Sign in / Sign up

Export Citation Format

Share Document