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Travis R. Blum

Bio: Travis R. Blum is a academic researcher at University of Wisconsin-Madison who has co-authored 7 publication(s) receiving 1582 citation(s). The author has an hindex of 4. Previous affiliations of Travis R. Blum include Harvard University & Hobart and William Smith Colleges. The author has done significant research in the topic(s): Photoredox catalysis & Cycloaddition.

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Papers
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Open accessJournal ArticleDOI: 10.1021/ACS.CHEMREV.6B00018
25 Apr 2016-Chemical Reviews
Abstract: The interaction between an electronically excited photocatalyst and an organic molecule can result in the genertion of a diverse array of reactive intermediates that can be manipulated in a variety of ways to result in synthetically useful bond constructions. This Review summarizes dual-catalyst strategies that have been applied to synthetic photochemistry. Mechanistically distinct modes of photocatalysis are discussed, including photoinduced electron transfer, hydrogen atom transfer, and energy transfer. We focus upon the cooperative interactions of photocatalysts with redox mediators, Lewis and Bronsted acids, organocatalysts, enzymes, and transition metal complexes.

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1,299 Citations


Open accessJournal ArticleDOI: 10.1126/SCIENCE.AAI8228
16 Dec 2016-Science
Abstract: Relatively few catalytic systems are able to control the stereochemistry of electronically excited organic intermediates. Here we report the discovery that a chiral Lewis acid complex can catalyze triplet energy transfer from an electronically excited photosensitizer. We applied this strategy to asymmetric [2 + 2] photocycloadditions of 2′-hydroxychalcones, using tris(bipyridyl) ruthenium(II) as a sensitizer. A variety of electrochemical, computational, and spectroscopic data rule out substrate activation by means of photoinduced electron transfer and instead support a mechanism in which Lewis acid coordination dramatically lowers the triplet energy of the chalcone substrate. We expect that this approach will enable chemists to more broadly apply their detailed understanding of chiral Lewis acid catalysis to stereocontrol in reactions involving electronically excited states.

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Topics: Lewis acids and bases (63%), Chiral Lewis acid (61%), Photoinduced electron transfer (55%) ...read more

187 Citations


Open accessJournal ArticleDOI: 10.1002/ANIE.201406393
06 Oct 2014-Angewandte Chemie
Abstract: We report a protocol for oxidative [3+2] cycloadditions of phenols and alkenes applicable to the modular synthesis of a large family of dihydrobenzofuran natural products. Visible-light-activated transition metal photocatalysis enables the use of ammonium persulfate as an easily handled, benign terminal oxidant. The broad range of organic substrates that are readily oxidized by photoredox catalysis suggests that this strategy may be applicable to a variety of useful oxidative transformations.

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Topics: Photoredox catalysis (55%), Cycloaddition (51%)

88 Citations


Open accessJournal ArticleDOI: 10.1126/SCIENCE.ABF5972
Travis R. Blum1, Travis R. Blum2, Travis R. Blum3, Liu Hao4  +20 moreInstitutions (5)
19 Feb 2021-Science
Abstract: Although bespoke, sequence-specific proteases have the potential to advance biotechnology and medicine, generation of proteases with tailor-made cleavage specificities remains a major challenge. We developed a phage-assisted protease evolution system with simultaneous positive and negative selection and applied it to three botulinum neurotoxin (BoNT) light-chain proteases. We evolved BoNT/X protease into separate variants that preferentially cleave vesicle-associated membrane protein 4 (VAMP4) and Ykt6, evolved BoNT/F protease to selectively cleave the non-native substrate VAMP7, and evolved BoNT/E protease to cleave phosphatase and tensin homolog (PTEN) but not any natural BoNT protease substrate in neurons. The evolved proteases display large changes in specificity (218- to >11,000,000-fold) and can retain their ability to form holotoxins that self-deliver into primary neurons. These findings establish a versatile platform for reprogramming proteases to selectively cleave new targets of therapeutic interest.

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Topics: Proteases (61%), Protease (57%)

6 Citations



Cited by
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Open accessJournal ArticleDOI: 10.1021/ACS.JOC.6B01449
Abstract: In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In a general sense, these approaches rely on the ability of metal complexes and organic dyes to convert visible light into chemical energy by engaging in single-electron transfer with organic substrates, thereby generating reactive intermediates. In this Perspective, we highlight the unique ability of photoredox catalysis to expedite the development of completely new reaction mechanisms, with particular emphasis placed on multicatalytic strategies that enable the construction of challenging carbon–carbon and carbon–heteroatom bonds.

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Topics: Photoredox catalysis (62%)

1,285 Citations


Journal ArticleDOI: 10.1021/ACS.CHEMREV.6B00644
Yoonsu Park, Youyoung Kim1, Sukbok Chang1Institutions (1)
04 Jan 2017-Chemical Reviews
Abstract: Catalytic transformation of ubiquitous C–H bonds into valuable C–N bonds offers an efficient synthetic approach to construct N-functionalized molecules. Over the last few decades, transition metal catalysis has been repeatedly proven to be a powerful tool for the direct conversion of cheap hydrocarbons to synthetically versatile amino-containing compounds. This Review comprehensively highlights recent advances in intra- and intermolecular C–H amination reactions utilizing late transition metal-based catalysts. Initial discovery, mechanistic study, and additional applications were categorized on the basis of the mechanistic scaffolds and types of reactions. Reactivity and selectivity of novel systems are discussed in three sections, with each being defined by a proposed working mode.

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Topics: Amination (52%)

1,150 Citations


Journal ArticleDOI: 10.1021/ACS.CHEMREV.8B00507
27 Feb 2019-Chemical Reviews
Abstract: C–H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material sciences, crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these C–H functionalizations required precious 4d or 5d transition metal catalysts. Given the cost-effective and sustainable nature of earth-abundant first row transition metals, the development of less toxic, inexpensive 3d metal catalysts for C–H activation has gained considerable recent momentum as a significantly more environmentally-benign and economically-attractive alternative. Herein, we provide a comprehensive overview on first row transition metal catalysts for C–H activation until summer 2018.

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892 Citations


Journal ArticleDOI: 10.1038/S41570-017-0052
Jack Twilton1, Chi Chip Le1, Patricia Zhang1, Megan H. Shaw1  +2 moreInstitutions (1)
05 Jul 2017-
Abstract: The merger of transition metal catalysis and photocatalysis, termed metallaphotocatalysis, has recently emerged as a versatile platform for the development of new, highly enabling synthetic methodologies. Photoredox catalysis provides access to reactive radical species under mild conditions from abundant, native functional groups, and, when combined with transition metal catalysis, this feature allows direct coupling of non-traditional nucleophile partners. In addition, photocatalysis can aid fundamental organometallic steps through modulation of the oxidation state of transition metal complexes or through energy-transfer-mediated excitation of intermediate catalytic species. Metallaphotocatalysis provides access to distinct activation modes, which are complementary to those traditionally used in the field of transition metal catalysis, thereby enabling reaction development through entirely new mechanistic paradigms. This Review discusses key advances in the field of metallaphotocatalysis over the past decade and demonstrates how the unique mechanistic features permit challenging, or previously elusive, transformations to be accomplished. Transition metal catalysis is well established as an enabling tool in synthetic organic chemistry. Photoredox catalysis has recently emerged as a method to effect reactions that occur through single-electron-transfer pathways. Here we review the combination of the two to show how this provides access to highly reactive oxidation states of transition metals and distinct activation modes that further enable the synthetic chemist.

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Topics: Photoredox catalysis (54%)

892 Citations


Journal ArticleDOI: 10.1021/ACS.CHEMREV.7B00183
01 Jun 2017-Chemical Reviews
Abstract: Flow chemistry involves the use of channels or tubing to conduct a reaction in a continuous stream rather than in a flask Flow equipment provides chemists with unique control over reaction parameters enhancing reactivity or in some cases enabling new reactions This relatively young technology has received a remarkable amount of attention in the past decade with many reports on what can be done in flow Until recently, however, the question, “Should we do this in flow?” has merely been an afterthought This review introduces readers to the basic principles and fundamentals of flow chemistry and critically discusses recent flow chemistry accounts

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846 Citations


Performance
Metrics

Author's H-index: 4

No. of papers from the Author in previous years
YearPapers
20211
20201
20181
20162
20151
20141

Top Attributes

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Author's top 5 most impactful journals

Science

2 papers, 193 citations

Journal of Organic Chemistry

1 papers, 1 citations

Chemical Reviews

1 papers, 1.2K citations

ChemInform

1 papers

Toxicon

1 papers, 1 citations

Network Information
Related Authors (1)
Tehshik P. Yoon

141 papers, 13.8K citations

78% related