Selectivity Control in Electron Spin Inversion Processes:  Regio- and Stereochemistry of Paternò−Büchi Photocyclo- additions as a Powerful Tool for Mapping Intersystem Crossing Processes

Griesbeck, Axel G.; Abe, Manabu; Bondock, Samir

doi:10.1021/ar040081u

Cited by 110 publications

(54 citation statements)

References 48 publications

(75 reference statements)

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“…ISC has also biochemical relevance as it is a key step in many biochemical reactions (e.g., oxygen binding to carrier proteins [26] ), harmful photochemical reactions of DNA strands, and has found application in phototherapies (e.g., photodynamical therapy [27] ). Furthermore, ISC is relevant to the study of combustion processes, where open-shell atoms (like oxygen) and radicals play a central role, in organic photochemistry, for example, in [212]-cycloadditions, [28] and in biomimetic catalysis. [29] Due to its increasing relevance in different disciplines, the number of studies on ISC has proliferated in the last years.…”

Section: Introductionmentioning

confidence: 99%

A general method to describe intersystem crossing dynamics in trajectory surface hopping

Mai

Marquetand

González

2015

Int J of Quantum Chemistry

254

400

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Intersystem crossing is a radiationless process that can take place in a molecule irradiated by UV‐Vis light, thereby playing an important role in many environmental, biological and technological processes. This paper reviews different methods to describe intersystem crossing dynamics, paying attention to semiclassical trajectory theories, which are especially interesting because they can be applied to large systems with many degrees of freedom. In particular, a general trajectory surface hopping methodology recently developed by the authors, which is able to include nonadiabatic and spin‐orbit couplings in excited‐state dynamics simulations, is explained in detail. This method, termed SHARC, can in principle include any arbitrary coupling, what makes it generally applicable to photophysical and photochemical problems, also those including explicit laser fields. A step‐by‐step derivation of the main equations of motion employed in surface hopping based on the fewest‐switches method of Tully, adapted for the inclusion of spin‐orbit interactions, is provided. Special emphasis is put on describing the different possible choices of the electronic bases in which spin‐orbit can be included in surface hopping, highlighting the advantages and inconsistencies of the different approaches. © 2015 Wiley Periodicals, Inc.

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Section: Introductionmentioning

confidence: 99%

A general method to describe intersystem crossing dynamics in trajectory surface hopping

Mai

Marquetand

González

2015

Int J of Quantum Chemistry

254

400

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“…In contrast, in the photocyclizations with the cyclic alkenes (1-phenylcyclopentene and 1-phenylcyclohexene) in which three new chiral centers are created, the cyclizations are highly diastereoselective, with only one out of the four possible diastereomers actually formed. Many theoretical [48] and experimental [49] pieces of work have shown that, in a triplet biradical, the ISC efficiency is highly conformation dependent. In an active conformation for efficient ISC, the two spin-bearing p-orbitals should be nearly orthogonal to each other.…”

Section: Wwwchemeurjorgmentioning

confidence: 99%

Intermolecular Photocyclizations of N‐(ω‐Hydroxyalkyl)tetrachlorophthalimide with Alkenes Leading to Medium‐ and Large‐Ring Heterocycles—Reaction Modes and Regio‐ and Stereoselectivity of the 1,n‐Biradicals

Shen

Yang

Chen

et al. 2010

Chemistry A European J

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A new photocyclization strategy by using intermolecular tandem reactions between N-(omega-hydroxyalkyl)-4,5,6,7-tetrachlorophthalimides (1, 2, and 3) and a series of acyclic and cyclic alkenes is reported. Electron transfer of the triplet-excited phthalimide with the alkene and regioselective trapping of the alkene cation radical by the hydroxyl group at the phthalimide side chain gives a triplet 1,n-biradical, which after intersystem crossing (ISC) leads to regio- and diastereoselective synthesis of polycyclic heterocycles with an N,O-containing medium to large ring. Regio- and diastereoselectivity in the cyclizations are clarified by unambiguous steric structure assignments of the products by X-ray diffraction or extensive 2D NMR measurements. The diastereoselectivity is decided by the stereochemical course of the ISC process of the triplet 1,n-biradicals. These intermolecular photoreactions also furnish a new strategy to generate triplet 1,n-biradicals. Therefore, in photoreactions of 1 and 2 with phenylcyclohexene, the unprecedented stereoselective formation of products by intramolecular hydrogen-atom transfer in the 1,n-biradical intermediate was found (9 and 23). These facts provide direct verification to the reaction pathways of the 1,n-biradicals and give a new insight into the factors deciding reaction-pathway partitioning and stereoselectivity.

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“…In this study, a photoaddition reaction between an aldehyde (or ketone) and an alkene known as Paternò-Büchi (PB) reaction [42][43][44][45] is considered. Its mechanism has been studied extensively both experimentally and theoretically [46][47][48][49][50][51][52][53][54]. Thus, this reaction is ideal for the present purpose of benchmarking the applicability to photochemical addition reactions.…”

Section: Introductionmentioning

confidence: 99%

Exploring Pathways of Photoaddition Reactions by Artificial Force Induced Reaction Method: A Case Study on the Paternò–Büchi Reaction

Maeda

Taketsugu

Morokuma

2013

Zeitschrift für Physikalische Chemie

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The present study demonstrates a priori prediction of the mechanism of Paternò-Büchi (PB) reaction by automated search for reaction pathways using the artificial force induced reaction (AFIR) method, for the simplest set of reactants, H 2 CO + C 2 H 4 . The search found all previously suggested pathways automatically without using any guess about the reaction mechanism. Even the reaction product was not assumed. In addition, a comprehensive view of the reaction path network obtained in the present extensive search gave new insights into the mechanism. Barriers on excited states explained the preference of the initial bonding sites. A seam of crossing between the lowest triplet and first singlet excited state is suggested to make a significant contribution to an intersystem crossing and the reaction mechanism of the present system.

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Selectivity Control in Electron Spin Inversion Processes: Regio- and Stereochemistry of Paternò−Büchi Photocyclo- additions as a Powerful Tool for Mapping Intersystem Crossing Processes

Cited by 110 publications

References 48 publications

A general method to describe intersystem crossing dynamics in trajectory surface hopping

A general method to describe intersystem crossing dynamics in trajectory surface hopping

Intermolecular Photocyclizations of N‐(ω‐Hydroxyalkyl)tetrachlorophthalimide with Alkenes Leading to Medium‐ and Large‐Ring Heterocycles—Reaction Modes and Regio‐ and Stereoselectivity of the 1,n‐Biradicals

Exploring Pathways of Photoaddition Reactions by Artificial Force Induced Reaction Method: A Case Study on the Paternò–Büchi Reaction

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