A Relay Strategy Actuates Pre-Existing Trisubstituted Olefins in Monoterpenoids to Form New Trisubstituted Olefins by Cross Metathesis

2019 ◽  
Author(s):  
Karim Bahou ◽  
D. Christopher Braddock ◽  
Adam G. Meyer ◽  
G. Paul Savage ◽  
Zhensheng Shi ◽  
...  
Keyword(s):  
Geometrical Isomer ◽  
Successful Implementation ◽  
Enantiomerically Pure ◽  
Cross Metathesis ◽  
Trisubstituted Olefins ◽  
The Cross ◽  
Trisubstituted Alkenes

<b><u>Abstract:</u></b> A retrosynthetic disconnection-reconnection analysis of epoxypolyenes – substrates that can undergo cyclization to podocarpane-type tricycles – reveals relay-actuated Δ<sup>6,7</sup>-functionalized monoterpenoid alcohols for ruthenium benzylidene catalyzed olefin cross metathesis with homoprenyl benzenes. Successful implementation of this approach provided several epoxypolyenes as expected (<i>E</i>:<i>Z</i>, ca. 2-3:1). The method is further generalized for the cross metathesis of pre-existing trisubstituted olefins in other relay-actuated Δ<sup>6,7</sup>-functionalized monoterpenoid alcohols with various other trisubstituted alkenes to form new trisubstituted olefins. Epoxypolyene cyclization of an enantiomerically pure, but geometrically impure, epoxypolyene substrate provides an enantiomerically pure, trans-fused, podocarpane-type tricycle (from the <i>E</i>-geometrical isomer).<br>

scholarly journals A Relay Strategy Actuates Pre-Existing Trisubstituted Olefins in Monoterpenoids to Form New Trisubstituted Olefins by Cross Metathesis

2019 ◽  
Author(s):  
Karim Bahou ◽  
D. Christopher Braddock ◽  
Adam G. Meyer ◽  
G. Paul Savage ◽  
Zhensheng Shi ◽  
...  
Keyword(s):  
Geometrical Isomer ◽  
Successful Implementation ◽  
Enantiomerically Pure ◽  
Cross Metathesis ◽  
Trisubstituted Olefins ◽  
The Cross ◽  
Trisubstituted Alkenes

<b><u>Abstract:</u></b> A retrosynthetic disconnection-reconnection analysis of epoxypolyenes – substrates that can undergo cyclization to podocarpane-type tricycles – reveals relay-actuated Δ<sup>6,7</sup>-functionalized monoterpenoid alcohols for ruthenium benzylidene catalyzed olefin cross metathesis with homoprenyl benzenes. Successful implementation of this approach provided several epoxypolyenes as expected (<i>E</i>:<i>Z</i>, ca. 2-3:1). The method is further generalized for the cross metathesis of pre-existing trisubstituted olefins in other relay-actuated Δ<sup>6,7</sup>-functionalized monoterpenoid alcohols with various other trisubstituted alkenes to form new trisubstituted olefins. Epoxypolyene cyclization of an enantiomerically pure, but geometrically impure, epoxypolyene substrate provides an enantiomerically pure, trans-fused, podocarpane-type tricycle (from the <i>E</i>-geometrical isomer).<br>

scholarly journals A Relay Strategy Actuates Pre-Existing Trisubstituted Olefins in Monoterpenoids for Cross-Metathesis with Trisubstituted Alkenes

2020 ◽  
Vol 85 (7) ◽  
pp. 4906-4917 ◽  
Author(s):  
Karim A. Bahou ◽  
D. Christopher Braddock ◽  
Adam G. Meyer ◽  
G. Paul Savage ◽  
Zhensheng Shi ◽  
...  
Keyword(s):  
Cross Metathesis ◽  
Trisubstituted Olefins ◽  
Trisubstituted Alkenes

Complete Stereocontrol in the Synthesis of Harmonine and Novel Analogues Facilitated by a Grubbs Z-Selective Cross-Metathesis Catalyst

2015 ◽  
Vol 68 (12) ◽  
pp. 1815 ◽  
Author(s):  
Steven-Alan G. Abel ◽  
Wesley J. Olivier ◽  
Richard L. Pederson ◽  
Alex C. Bissember ◽  
Jason A. Smith
Keyword(s):  
The Self ◽  
Metathesis Reaction ◽  
Cross Metathesis ◽  
Metathesis Catalyst ◽  
The Cross

(R)-Harmonine was synthesised in 15 % overall yield via a six-step sequence exploiting a Z-selective cross-metathesis reaction as its centrepiece. By this strategy, the cis-olefin present in the target could be installed exclusively. The use of an alcohol and an ester as the amine precursors was crucial for isolating the cross-metathesis product from the self-metathesis products. This method was also used to prepare two novel analogues of harmonine.

Low Catalyst Loading in the Cross Metathesis of Olefins with Methyl Vinyl Ketone

Synlett ◽  
2013 ◽  
Vol 24 (10) ◽  
pp. 1193-1196 ◽  
Author(s):  
Christian Slugovc ◽  
Muddasar Abbas ◽  
Anita Leitgeb
Keyword(s):  
Vinyl Ketone ◽  
Methyl Vinyl Ketone ◽  
Catalyst Loading ◽  
Methyl Vinyl ◽  
Cross Metathesis ◽  
The Cross ◽  
Low Catalyst Loading

scholarly journals Computational study of productive and non-productive cycles in fluoroalkene metathesis

2015 ◽  
Vol 11 ◽  
pp. 2150-2157 ◽  
Author(s):  
Markéta Rybáčková ◽  
Jan Hošek ◽  
Ondřej Šimůnek ◽  
Viola Kolaříková ◽  
Jaroslav Kvíčala
Keyword(s):  
Computational Study ◽  
Catalytic Cycle ◽  
Dft Study ◽  
Cross Metathesis ◽  
High Preference ◽  
The Cross

A detailed DFT study of the mechanism of metathesis of fluoroethene, 1-fluoroethene, 1,1-difluoroethene, cis- and trans-1,2-difluoroethene, tetrafluoroethene and chlorotrifluoroethene catalysed with the Hoveyda–Grubbs 2nd generation catalyst was performed. It revealed that a successful metathesis of hydrofluoroethenes is hampered by a high preference for a non-productive catalytic cycle proceeding through a ruthenacyclobutane intermediate bearing fluorines in positions 2 and 4. Moreover, the calculations showed that the cross-metathesis of perfluoro- or perhaloalkenes should be a feasible process and that the metathesis is not very sensitive to stereochemical issues.

scholarly journals Equilibrium data for the cross-metathesis of methyl oleate with cinnamaldehyde

Data in Brief ◽  
2018 ◽  
Vol 20 ◽  
pp. 190-195
Author(s):  
Pablo D. Nieres ◽  
Andrés F. Trasarti ◽  
Carlos R. Apesteguía
Keyword(s):  
Methyl Oleate ◽  
Cross Metathesis ◽  
Equilibrium Data ◽  
The Cross

Regulation of the degree of blockiness of the norbornene–cyclooctene copolymer synthesized via the cross-metathesis reaction

2016 ◽  
Vol 58 (3) ◽  
pp. 292-297 ◽  
Author(s):  
Yu. I. Denisova ◽  
M. L. Gringolts ◽  
L. B. Krentsel’ ◽  
G. A. Shandryuk ◽  
A. D. Litmanovich ◽  
...  
Keyword(s):  
Metathesis Reaction ◽  
Cross Metathesis ◽  
The Cross

Synthesis of Trisubstituted Alkenes via Olefin Cross-Metathesis

1999 ◽  
Vol 1 (11) ◽  
pp. 1751-1753 ◽  
Author(s):  
Arnab K. Chatterjee ◽  
Robert H. Grubbs
Keyword(s):  
Cross Metathesis ◽  
Trisubstituted Alkenes

An Atom-Economic and Stereospecific Access to Trisubstituted Olefins through Enyne Cross Metathesis Followed by 1,4-Hydrogenation

Synlett ◽  
2018 ◽  
Vol 29 (06) ◽  
pp. 785-792 ◽  
Author(s):  
Hans-Günther Schmalz ◽  
Friederike Ratsch
Keyword(s):  
Functional Group ◽  
Cross Metathesis ◽  
Broad Scope ◽  
Trisubstituted Olefins

The combination of intermolecular enyne cross metathesis and subsequent 1,4-hydrogenation opens a stereocontrolled and atom-economic access to trisubstituted olefins. By investigating different combinations of functionalized alkyne and alkene substrates, we found that the outcome (yield, E/Z ratio) of the Grubbs II-catalyzed enyne cross-metathesis step depends on the substrate’s structure, the amount of the alkene (used in excess), and the (optional) presence of ethylene. In any case, the 1,4-hydrogenation, catalyzed by 1,2-di­methoxybenzene-Cr(CO)3, proceeds stereospecifically to yield exclusively the E-products from both the E- and Z-1,3-diene intermediates obtained by metathesis. A rather broad scope and functional group compatibility of the method is demonstrated by means of 15 examples.

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