Localized Crystallization of Enantiomeric Organic Compounds on Chiral Micro‐patterns from Various Organic Solutions

Lingenfelder, Magalí; Bejarano‐Villafuerte, Ángela; Meijden, Maarten W. van der; Kellogg, Richard M.; Amabilino, David B.

doi:10.1002/chem.201303062

Cited by 3 publications

(1 citation statement)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The enantiomerically pure material forms rows of dimers oriented along the ⟨11̅1⟩ crystallographic axis of Au. On the other hand, the racemate forms large enantiomorphous domains, and each unit cell apparently contains 8 molecules. , …”

Section: Resultsmentioning

confidence: 99%

Practical Stereochemistry

Kellogg

2017

Acc. Chem. Res.

Self Cite

View full text Add to dashboard Cite

The relationship between fundamental and applied is often uneasy, particularly in modern political climates. A familiar political view, aimed negatively at the scientific community, is that the former is a waste of money whereas the latter gives value for investment. The answer that fundamental is required as the basis for practical suffers from the fact that the timelines between fundamental and practical are often long and the routes contorted and unexpected. This has been my experience. In this Account, examples are given from the research in which I have been involved wherein quite fundamental considerations have led to various applications. The longer the time, the clearer and broader the relationship. Fundamental can and does lead to application. They need and depend on each other. I have seen this both from the side of academia and from small companies. In the course of the past 40 plus years, I have been involved in various aspects of stereochemistry and, in particular, chirality. It has been rewarding to see that several of the developments, most originally grounded in fundamental research considerations, have been used in the chemical community and given new dimensions and often practical applications by others. In this Account, a path-not planned deliberately by me-from orbital symmetry and Woodward-Hoffmann rules through crown ethers to conformational analysis to diastereomeric resolutions to deracemizations powered by Ostwald ripening and the Gibbs-Thomson effect to nucleation to helicenes is described. In order of discussion, the orbital symmetry aspects have via an unusual and unpredicted path has resulted in, among other things, a synthesis of hindered alkenes useful for the production of molecular motors. The crown ether aspects led to discovery of the utility of cesium salts particularly for racemization sensitive nucleophilic substitutions. Work on diastereomeric resolutions has concentrated on the mechanistic as well as practical/commercial aspects of the use of multiple resolving agents (Dutch resolution). During this work the complex relationship between nucleation and chirality in diastereomeric resolutions began to reveal itself. In general, nucleation, especially with involvement of chirality, is a topical challenge that has attracted the attention of many groups. The contribution of this knowledge to the development of attrition driven deracemizations of racemizable conglomerates is described. This remarkable technology allows, without intervention of chiral aids, conversion of certain racemates in quantitative yield and absolute enantiomeric excess to a single enantiomer. From a practical standpoint, this methodology has been used for the production in enantiomerically pure form of commercially interesting compounds like naproxen and clopidogrel (Plavix). Finally an STM investigation of the nucleation behavior of a helicene, prepared via a remarkably short and efficient route, on a metal surface is described.

show abstract

Section: Resultsmentioning

confidence: 99%

Practical Stereochemistry

Kellogg

2017

Acc. Chem. Res.

Self Cite

View full text Add to dashboard Cite

show abstract

Patterning of Surfaces for Supramolecular Chemistry and Template Effects

2016

Supramolecular Chemistry at Surfaces

View full text Add to dashboard Cite

A number of techniques are available for the controlled preparation of surfaces comprising areas of defined shape and size that contain chemical functionality that can lead to covalent or non-covalent growth of mono- and multi-layers. These lithographies will be presented, with special emphasis on scanning probe lithographies and microcontact printing. These methods afford multifunctional surfaces that can either behave differently to single component and strictly mixed monolayers or simply aid in the identification of layer growth and properties compared to a reference layer. It will be shown that the monolayers that are formed under certain patterning conditions do not necessarily have the same structure as those formed by total monolayer-forming techniques. The deposition of molecules on (sub)micropatterned surfaces can lead to very distinct outcomes during self-assembly processes when compared with more expansive uniform surfaces. The use of patterns for determining binding at interfaces is a useful method whereby internal references can be directly compared with multiple host areas. The spontaneous formation of patterns for the formation of thin films is an emerging area where the combination of top-down and bottom-up methods in air and vacuum can be combined to great effect.

show abstract