A Simple Way to Predict the Products of Topochemical Photoreactions on the Basis of Force Field Calculations

Angermund, Klaus; Nolte, Matthias; Klopp, Ingo

doi:10.1002/anie.199113541

Cited by 10 publications

(7 citation statements)

References 13 publications

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“…A different approach was employed by McBride using molecular mechanics to ascertain the ease of migration of fragments within the reaction cavity in free radical dissociations. A recent communication describes the use of molecular mechanics to obtain the difference in energy of the most stable conformation of a final product molecule in a crystal lattice and the geometry-optimized conformation outside of the lattice 18a.…”

Section: Interpretative Discussionmentioning

confidence: 99%

“…A recent communication describes the use of molecular mechanics to obtain the difference in energy of the most stable conformation of a final product molecule in a crystal lattice and the geometryoptimized conformation outside of the lattice. 17 Scheffer in an elegant study has compared the ease of two dibenzobarrelene esters to twist toward a bridged intermediate; in this he used van der Waals attractive and repulsive forces. 18a In a more recent study he has suggested control by steric compression effects in a 2 + 2 cycloaddition.…”

Section: Interpretative Discussionmentioning

confidence: 99%

“…Crystallization from pentane gave 24.5 mg (23%) of colorless crystals, mp 108-109 °C. Fraction 2 contained 36.1 mg (30%) of 5-tert-butyl-3-methoxy-4,4-diphenylcyclohex-2-en-1-one (17). Crystallization from hexane gave 32.8 mg (27%) of colorless crystals, mp 154-155 °C.…”

Section: -(P-cyanophenylmentioning

confidence: 99%

“…The spectral characteristics of 5-tert-butyl-3-methoxy-4,4-diphenylcyclohex-2-en-1-one (17) were the following: 1 H NMR (CDCl3, 300 MHz) δ 7. 63-7.50 (m, 4H), 7.43-7.22 (m, 6H), 5.58 (s, 1H), 3.44 (s, 3H), 3.21 (dd, J ) 12.5, 3.3 Hz, 1H), 2.50 (dd, J ) 16.4, 3.3 Hz, 1H), 2.40 (dd, J ) 16.4, 12.5 Hz, 1H), 0.56 (s, 9H); MS m/e 334.1937 (calcd for C 23H26O2, 334.1933); IR (film) 1649, 1598, 1211 cm -1 .…”

Section: -(P-cyanophenylmentioning

confidence: 99%

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Photochemistry in a Crystalline Cage. Control of the Type-B Bicyclic Reaction Course: Mechanistic and Exploratory Organic Photochemistry¹^,²

and

Sebek

1997

J. Am. Chem. Soc.

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Our current theories on crystal lattice control of organic photochemistry were subjected to studies of type-B rearrangement of bicyclo[3.1.0]hex-3-en-2-ones. A first finding was that the solid state photochemistry differed dramatically from that in solution. One of our past observations in this bicyclic photochemistry in solution was that the six-membered ring, type B, zwitterion was a ubiquitous intermediate. This intermediate invariably underwent a preferential migration of an aryl group to carbon-2 relative to carbon-4 with formation of a 2,3-disubstituted phenol, a result deriving from electronic effects. In contrast, the crystal lattice photochemistry revealed a regioselectivity depending on the surrounding lattice rather than electronics. Perhaps an even more dramatic difference was an observation of the dependence of reactant stereochemistry. Thus, in solution, for 6,6-disubstituted bicyclics with two different groups at C-6, a common zwitterion is formed and the same photoproduct is formed independent of reactant stereochemistry. In crystal lattices the endo and exo stereoisomers of the 6,6-disubstituted bicyclics react differently and the group originally endo tends to migrate after three-ring opening to the zwitterion. The experimental results were paralleled with a theoretical analysis. This consisted of generation of a “mini crystal lattice” with sufficient lattice molecules to completely surround a central, reacting electronically excited state molecule. Then computational extraction of the central molecule and replacement by a transition structure afford a model of the reacting excited state inside the crystal lattice. Overlap of this species with the lattice neighbors and energy computations are then possible. These permit prediction and understanding of excited state crystal lattice reactivity on a quantitative basis.

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Section: Interpretative Discussionmentioning

confidence: 99%

Section: Interpretative Discussionmentioning

confidence: 99%

Section: -(P-cyanophenylmentioning

confidence: 99%

Section: -(P-cyanophenylmentioning

confidence: 99%

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Photochemistry in a Crystalline Cage. Control of the Type-B Bicyclic Reaction Course: Mechanistic and Exploratory Organic Photochemistry¹^,²

and

Sebek

1997

J. Am. Chem. Soc.

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“…What interactions in a crystal lattice allow some reactions to occur readily and yet forbid other similar transformations from occurring at all? This question has led researchers to develop a variety of theoretical and computational models for the study of crystal reactivity. − We now report our application of a new computational approach to a highly selective solid-state carbene rearrangement. The solid-state phototransformation of diazo 1 to stilbene 3 occurs with very high stereoselectivity (>96%) in a crystalline lattice .…”

mentioning

confidence: 99%

Combining Quantum Mechanical Reaction Pathways with Force Field Lattice Interactions To Model a Solid-State Phototransformation

1997

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Solvent‐Free Photosynthesis of Cyclobutanes: Photodimerization of Crystalline Olefins

Natarajan

Ramamurthy

2009

Patai's Chemistry of Functional Groups

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Introduction Photodimerization of Cinnamic Acids: Emergence of Topochemical Postulates Photodimerization of Coumarins, Styrylcoumarins and Benzylidenecyclopentanones Reaction Cavity Concept: Role of Empty Space and Immediate Neighbors Fine Tuning of Topochemical Postulates Impact of Excitation on Molecular Geometry and Intermolecular Arrangement Crystal Engineering Does Dimerization Precede Geometric Isomerization? Single Crystal to Single Crystal Photodimerization of Olefins Concluding Remarks Appendix: More Examples of Solid State Photodimerization of Olefins Acknowledgment

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A Simple Way to Predict the Products of Topochemical Photoreactions on the Basis of Force Field Calculations

Cited by 10 publications

References 13 publications

Photochemistry in a Crystalline Cage. Control of the Type-B Bicyclic Reaction Course: Mechanistic and Exploratory Organic Photochemistry¹^,²

Photochemistry in a Crystalline Cage. Control of the Type-B Bicyclic Reaction Course: Mechanistic and Exploratory Organic Photochemistry¹^,²

Combining Quantum Mechanical Reaction Pathways with Force Field Lattice Interactions To Model a Solid-State Phototransformation

Solvent‐Free Photosynthesis of Cyclobutanes: Photodimerization of Crystalline Olefins

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A Simple Way to Predict the Products of Topochemical Photoreactions on the Basis of Force Field Calculations

Cited by 10 publications

References 13 publications

Photochemistry in a Crystalline Cage. Control of the Type-B Bicyclic Reaction Course: Mechanistic and Exploratory Organic Photochemistry1,2

Photochemistry in a Crystalline Cage. Control of the Type-B Bicyclic Reaction Course: Mechanistic and Exploratory Organic Photochemistry1,2

Combining Quantum Mechanical Reaction Pathways with Force Field Lattice Interactions To Model a Solid-State Phototransformation

Solvent‐Free Photosynthesis of Cyclobutanes: Photodimerization of Crystalline Olefins

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Photochemistry in a Crystalline Cage. Control of the Type-B Bicyclic Reaction Course: Mechanistic and Exploratory Organic Photochemistry¹^,²

Photochemistry in a Crystalline Cage. Control of the Type-B Bicyclic Reaction Course: Mechanistic and Exploratory Organic Photochemistry¹^,²