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Darrin M. Flanigan

Other affiliations: Oregon State University
Bio: Darrin M. Flanigan is an academic researcher from Colorado State University. The author has contributed to research in topics: Enantioselective synthesis & Lactam. The author has an hindex of 5, co-authored 9 publications receiving 1160 citations. Previous affiliations of Darrin M. Flanigan include Oregon State University.

Papers
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TL;DR: In this paper, NHC-catalyzed nucleophilic dearomatization of alkyl pyridiniums has been achieved to generate 1,4-dihydropyridines with high enantioselectivity.
Abstract: NHC-catalyzed nucleophilic dearomatization of alkyl pyridiniums has been achieved to generate 1,4-dihydropyridines with high enantioselectivity. This is a rare example of catalytic, asymmetric addition of a nucleophile to the activated pyridinium that prefers C-4 functionalization leading to the 1,4-dihydropyridine with high selectivity.

55 citations

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TL;DR: A concise enantioselective synthesis of (-)-paroxetine (Paxil) and (-)-femoxetines has been achieved using a N-heterocyclic carbene catalyzed homoenolate addition to a nitroalkene followed by in situ reduction of the nitro-group to rapidly access δ-lactams.

20 citations

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TL;DR: 7,7'-Dihydroxy-8,8'-biquinolyl (azaBINOL) was prepared from 2-chloroaniline in four steps: the Skraup reaction, Ni-catalyzed reductive coupling of 8-chloroquinoline, Pd(II)-Catalyzed double C-H functionalization of 8,8-biquinlyl mediated by PhI(OAc)(2), and saponification.

18 citations

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TL;DR: A small library of triazolylidene-boranes that differ only in the nature of the aryl group on the external nitrogen atom was prepared and allowed a structure-reactivity relationship with regard to the substitution pattern of the NHC to be established and the role of electronic effects in the reactivity of NHC-boryl radicals to be probed.
Abstract: A small library of triazolylidene-boranes that differ only in the nature of the aryl group on the external nitrogen atom was prepared. Their reactivity as hydrogen-atom donors, as well as that of the corresponding N-heterocyclic carbene (NHC)-boryl radicals toward methyl acrylate and oxygen, was investigated by laser flash photolysis, molecular orbital calculations, and ESR spin-trapping experiments, and benchmarked relative to the already known dimethyltriazolylidene-borane. The new NHC-boranes were also used as co-initiators for the Type I photopolymerization of acrylates. This allowed a structure-reactivity relationship with regard to the substitution pattern of the NHC to be established and the role of electronic effects in the reactivity of NHC-boryl radicals to be probed. Although their rate of addition to methyl acrylate depends on their electronegativity, the radicals are all nucleophilic and good initiators for photopolymerization reactions.

11 citations


Cited by
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TL;DR: This review introduces readers to the basic principles and fundamentals of flow chemistry and critically discusses recent flow chemistry accounts.
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

1,192 citations

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TL;DR: This review provides an overview on the use of anodic electrochemical methods for expediting the development of carbon-hydrogen functionalization and carbon-nitrogen bond formation strategies and aims to provide inspiration for future synthetic applications in the field of electrosynthesis.
Abstract: Conventional methods for carrying out carbon–hydrogen functionalization and carbon–nitrogen bond formation are typically conducted at elevated temperatures, and rely on expensive catalysts as well as the use of stoichiometric, and perhaps toxic, oxidants. In this regard, electrochemical synthesis has recently been recognized as a sustainable and scalable strategy for the construction of challenging carbon–carbon and carbon–heteroatom bonds. Here, electrosynthesis has proven to be an environmentally benign, highly effective and versatile platform for achieving a wide range of nonclassical bond disconnections via generation of radical intermediates under mild reaction conditions. This review provides an overview on the use of anodic electrochemical methods for expediting the development of carbon–hydrogen functionalization and carbon–nitrogen bond formation strategies. Emphasis is placed on methodology development and mechanistic insight and aims to provide inspiration for future synthetic applications in the field of electrosynthesis.

626 citations

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TL;DR: The most important results published up to the end of 2013 are briefly summarized, while the majority of this Review focuses on findings reported within the last three years.
Abstract: Discovered in 2005, cyclic (alkyl)(amino)carbenes (CAACs) are among the most nucleophilic (σ donating) and also electrophilic (π-accepting) stable carbenes known to date. These properties allow them to activate a variety of small molecules and enthalpically strong bonds, to stabilize highly reactive main-group and transition-metal diamagnetic and paramagnetic species, and to bind strongly to metal centers, which gives rise to very robust catalysts. The most important results published up to the end of 2013 are briefly summarized, while the majority of this Review focuses on findings reported within the last three years.

528 citations

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TL;DR: With the ever growing toolbox for epoxide polymerization, a "polyether universe" may be envisaged that in its structural diversity parallels the immense variety of structural options available for polymers based on vinyl monomers with a purely carbon-based backbone.
Abstract: The review summarizes current trends and developments in the polymerization of alkylene oxides in the last two decades since 1995, with a particular focus on the most important epoxide monomers ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO). Classical synthetic pathways, i.e., anionic polymerization, coordination polymerization, and cationic polymerization of epoxides (oxiranes), are briefly reviewed. The main focus of the review lies on more recent and in some cases metal-free methods for epoxide polymerization, i.e., the activated monomer strategy, the use of organocatalysts, such as N-heterocyclic carbenes (NHCs) and N-heterocyclic olefins (NHOs) as well as phosphazene bases. In addition, the commercially relevant double-metal cyanide (DMC) catalyst systems are discussed. Besides the synthetic progress, new types of multifunctional linear PEG (mf-PEG) and PPO structures accessible by copolymerization of EO or PO with functional epoxide comonomers are presented as well as complex bra...

523 citations

Journal ArticleDOI
TL;DR: This review provides a comprehensive summary of organocatalysis in inert C-H bond functionalization over the past two decades as well as those activated benzylic, allylic, and C- H bonds alpha to the heteroatom such as nitrogen and oxygen.
Abstract: As two coexisting and fast-growing research fields in modern synthetic chemistry, the merging of organocatalysis and C–H bond functionalization is well foreseeable, and the joint force along this line has been demonstrated to be a powerful approach in making inert C–H bond functionalization more viable, predictable, and selective. In this review, we provide a comprehensive summary of organocatalysis in inert C–H bond functionalization over the past two decades. The review is arranged by types of inert C–H bonds including alkane C–H, arene C–H, and vinyl C–H as well as those activated benzylic C–H, allylic C–H, and C–H bonds alpha to the heteroatom such as nitrogen and oxygen. In each section, the discussion is classified by the explicit organocatalytic mode involved.

484 citations