Direct Catalytic Anti-Markovnikov Hydroetherification of Alkenols

Hamilton, David; Nicewicz, David A.

doi:10.1021/ja309635w

Cited by 343 publications

(201 citation statements)

References 33 publications

(46 reference statements)

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“…6C) (64). This type of bond construction commonly relies on acid catalysts, such as 6 , that direct bond formation to the most substituted carbon of the alkene to yield the Markovnikov product.…”

Section: Photogenerated Radical Ionsmentioning

confidence: 99%

Solar Synthesis: Prospects in Visible Light Photocatalysis

Schultz

Yoon

2014

Science

2,171

1,013

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Chemists have long aspired to synthesize molecules the way that plants do — using sunlight to facilitate the construction of complex molecular architectures. Nevertheless, the use of visible light in photochemical synthesis is fundamentally challenging because organic molecules tend not to interact with the wavelengths of visible light that are most strongly emitted in the solar spectrum. Recent research has begun to leverage the ability of visible light absorbing transition metal complexes to catalyze a broad range of synthetically valuable reactions. In this review, we highlight how an understanding of the mechanisms of photocatalytic activation available to these transition metal complexes, and of the general reactivity patterns of the intermediates accessible via visible light photocatalysis, has accelerated the development of this diverse suite of reactions.

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Section: Photogenerated Radical Ionsmentioning

confidence: 99%

Solar Synthesis: Prospects in Visible Light Photocatalysis

Schultz

Yoon

2014

Science

2,171

1,013

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“…Such two reactions create new covalent bonds between the carbon atoms in PDMS and the oxygen atoms on RGO, thus greatly strengthening the interface and 131 improving the mechanical properties of the nano-carbon composites. These formations have also been shown in past work with photon-assisted [248][249][250]. Further, the XPS studies show direct correlation between bond formation and overall improvement in mechanical properties such as Young's modulus, strain energy density, toughness, and load transfer.…”

Section: Resultssupporting

confidence: 76%

Near infrared photon-assisted polymerization of advanced polymer composites.

Xu¹

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This dissertation describes a novel method to develop polymer composites using near infrared (NIR) photon-assisted polymerization and nanoscale reinforcement. We used multi-walled carbon nanotubes (MWNTs), reduced graphene oxide (RGO), and graphene nanoplatelets (GNPs) to make polymer composites, and explored in-situ NIR photon assisted heating of these nano carbons to enhance polymerization of the nanocarbon/polymer interface, thus achieving significant load transfer and improved vii mechanical properties. To specify, nano-carbon was dispersed into the polymer matrix by shear or evaporation mixing method to attain a uniform distribution in the prepared thin film composite. The thin film was exposed to NIR light during polymerization instead of conventional oven based heating. NIR was effectively absorbed by nano-carbons and also atoms from polymer molecule; the induced photo-thermal heat was transferred into the polymer matrix to induce polymerization of the composite and the covalent bonding between nano-carbons and polymer matrix at the interface. Scanning electron microscope (SEM), Raman spectroscopy, and RSA were used to evaluate the load transfer and mechanical strength of the polymerized composite samples. Investigating first the nanotube/polymer composites synergized by NIR photon-assisted polymerization, largeRaman shifts (20 cm -1 wavenumber for up to 80% strains) of the 2D band were recorded for the NIR light polymerized samples and an increase in Young's modulus by ~130%was measured for the 1 wt. MWNT/poly(dimethylsiloxane) (PDMS) composites. While at first it was thought that NIR radiation during polymerization heated the nano-carbons inside resulting in strengthening of the nano-carbon/polymer interface, it was seen after further experimentation with graphene reinforcements that other light induced bonding effects apart from heat were also responsible.Raman spectroscopy revealed that mixing graphene in polymer has a profound As a demonstration of applications, PDMS/RGO/PDMS sandwiched structure strain sensor, a demo application of the NIR photon-assisted polymerization was investigated. High sensitivity and high Gauge Factor (GF) are addressed. These results shown in this dissertation suggest that the NIR photon-assisted polymerization can be practically developed as a scalable nanomanufacturing technique to create large panels of advanced composites with strong interface and better mechanical properties compared to conventional oven based heating methods. It also suggests that it is possible to fabricate large-scale flexible smart device like high sensitivity strain sensors.xi

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“…[42,43] The photoredox step relies on the use of an organic catalyst, namely, the Fukuzumi acridinium salt. The use of such catalysts has flourished lately owing to the broad range of reactions accessible and the low cost of these compounds.…”

Section: Multiple-bond-centered Radical-mediated Reactivitymentioning

confidence: 99%

“…[43,45] Indeed, they reported the direct anti-Markovnikov addition of carboxylic acids to alkenes under similar conditions to those for their hydroetherification method. [42] The HAD used initially (2-phenylmalononitrile) was replaced by sodium benzene sulfinate, which served as the HAD as well as a base to promote the reaction.…”

Section: Multiple-bond-centered Radical-mediated Reactivitymentioning

confidence: 99%