Cross‐Metathesis in Natural Products Synthesis

Prunet, Joëlle; Grimaud, Laurence

doi:10.1002/9783527629626.ch10

Cited by 23 publications

(11 citation statements)

References 67 publications

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“…The findings outlined herein offer additional evidence regarding the unique ability of stereogenic-at-Mo mono-aryloxypyrrolides to effect olefin metathesis reactions extends beyond enantioselective processes xxix , with efficiency and selectivity levels that are not achievable with other catalyst classes. The catalytic processes described herein are expected to impact significantly the ventures that require stereoselective synthesis of organic molecules xxx , xxxi .…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Catalytic Z-selective olefin cross-metathesis for natural product synthesis

Meek

O’Brien

Llaveria

et al. 2011

Nature

373

218

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Alkenes are found in a great number of biologically active molecules and are employed in numerous transformations in organic chemistry. Many olefins exist as E or higher energy Z isomers. Catalytic procedures for stereoselective formation of alkenes are therefore valuable; nonetheless, methods for synthesis of 1,2-disubstituted Z olefins are scarce. Here we report catalytic Z-selective cross-metathesis reactions of terminal enol ethers, which have not been reported previously, and allylic amides, employed thus far only in E-selective processes; the corresponding disubstituted alkenes are formed in up to >98% Z selectivity and 97% yield. Transformations, promoted by catalysts that contain the highly abundant and inexpensive molybdenum, are amenable to gram scale operations. Use of reduced pressure is introduced as a simple and effective strategy for achieving high stereoselectivity. Utility is demonstrated by syntheses of anti-oxidant C18 (plasm)-16:0 (PC), found in electrically active tissues and implicated in Alzheimer’s disease, and the potent immunostimulant KRN7000.

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Section: Conclusion and Discussionmentioning

confidence: 99%

Catalytic Z-selective olefin cross-metathesis for natural product synthesis

Meek

O’Brien

Llaveria

et al. 2011

Nature

373

218

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“…Similarly, the monosubstituted enone dimerized under the metathesis conditions. The optimized yield of the desired E trisubstituted enone 3 was only 47%, because Z enone 1 isomerized into the unreactive E isomer in the presence of metathesis catalysts, showing the limitations of CM for the synthesis of highly hindered trisubstituted olefins . We thus devised an intramolecular version of this coupling reaction, relying on a silicon-tether ring-closing metathesis.…”

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confidence: 99%

Novel Synthesis of Trisubstituted Olefins for the Preparation of the C16–C30 Fragment of Dolabelide C

et al. 2018

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A silicon-tether ring-closing metathesis strategy is reported for the synthesis of trisubstituted olefins flanked by allylic or homoallylic alcohols, which are difficult to obtain by classical ring-closing or cross-metathesis reactions. In addition, a novel Peterson olefination reaction has been developed for the preparation of the allyldimethylsilane precursors, which are versatile synthetic intermediates. This method was then applied to the synthesis of the C16–C30 fragment of dolabelide C.

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“…89 The superior activity of CAAC catalysts in cross-metathesis processes with acrylonitrile was successfully extended to methyl oleate 5 and 1-decene 3a, affording the corresponding olefins 17 and 18 (Scheme 28). 90 Acrylates (type II olefins 78 ) have a significant number of applications 91 but have poor reactivity in metathesis transformations, as shown with Grubbs second-generation catalysts which require activation by a copper additive. 92,93 Having found that CAAC catalysts allowed for improved catalytic activities in the cross metathesis of ethyl As shown in Scheme 30, these challenging cross-metathesis reactions between electron-deficient methyl acrylate and acrylonitrile with methyl 9-undecenoate 3b was readily extended to bis(CAAC)Ru indenylidene precatalysts.…”

Section: (Caac)ruthenium Catalysts In Olefin Metathesismentioning

confidence: 99%