Primary‐Amine‐Catalyzed Enantioselective Intramolecular Aldolizations

Zhou, Jian; Wakchaure, Vijay N.; Kraft, Philip; List, Benjamin

doi:10.1002/anie.200802497

Cited by 161 publications

(62 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…6). This class of compounds, derived from natural sources, has been identified as a promising alternative to other amino‐catalysts such as proline . ( A ) As well as its quinidine diasteteroisomer activate various carbonyl compounds with a consistently high level of stereocontrol.…”

Section: Resultsmentioning

confidence: 99%

Beyond static structures: Putting forth REMD as a tool to solve problems in computational organic chemistry

et al. 2015

View full text Add to dashboard Cite

Computational studies of organic systems are frequently limited to static pictures that closely align with textbook style presentations of reaction mechanisms and isomerization processes. Of course, in reality chemical systems are dynamic entities where a multitude of molecular conformations exists on incredibly complex potential energy surfaces (PES). Here, we borrow a computational technique originally conceived to be used in the context of biological simulations, together with empirical force fields, and apply it to organic chemical problems. Replica‐exchange molecular dynamics (REMD) permits thorough exploration of the PES. We combined REMD with density functional tight binding (DFTB), thereby establishing the level of accuracy necessary to analyze small molecular systems. Through the study of four prototypical problems: isomer identification, reaction mechanisms, temperature‐dependent rotational processes, and catalysis, we reveal new insights and chemistry that likely would be missed using static electronic structure computations. The REMD‐DFTB methodology at the heart of this study is powered by i‐PI, which efficiently handles the interface between the DFTB and REMD codes. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

show abstract

Section: Resultsmentioning

confidence: 99%

Beyond static structures: Putting forth REMD as a tool to solve problems in computational organic chemistry

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Later, the scope of this methodology was successfully extended to the intramolecular version by List and coworkers [14]. By employing 9-amino-9-deoxyepiquinine 24 as a catalyst (20 mol%) and an acid cocatalyst (AcOH, 60 mol%), 5-substituted-3methyl-2-cyclohexene-1-ones (26) were obtained with high enantioselectivity (up to 94% ee) from the diketones 25 via the intramolecular aldol reaction (Scheme 8.8).…”

Section: Direct Aldol Reactionsmentioning

confidence: 99%

Cinchona‐Catalyzed Nucleophilic 1,2‐Addition to CO and CN Bonds

Jang

Lee

Song

2009

Cinchona Alkaloids in Synthesis and Catalysis

View full text Add to dashboard Cite

The enantioselective nucleophilic addition of prochiral C¼O and C¼N moieties to the corresponding saturated chiral products is one of the most important stereoselective transformations on both the laboratory and the industrial scale. Although, over the past few decades, remarkable scientific achievements have been made in these research areas by using a variety of transitional metal-based catalysts, the sensitivity of the reaction to moisture and oxygen, as well as the toxic metal contamination of the product, usually restrict its practical application. Thus, currently, there is much interest in chiral organocatalysts, as they tend to be less toxic and more environmental friendly than traditional metal-based catalysts [1]. They are usually robust and thus tolerate moisture and oxygen, so that they usually do not demand any special reaction conditions.The naturally occurring cinchona alkaloids (Figure 8.1), as described in other chapters of this book, have proven to be powerful organocatalysts in most major chemical reactions. They possess diverse chiral skeletons and are easily tunable for diverse catalytic reactions through different mechanisms, which make them privileged organocatalysts. The vast synthetic potential of cinchona alkaloids and their derivatives in the asymmetric nucleophilic addition of prochiral C¼O and C¼N bonds has also been well demonstrated over the last decade.In this chapter, the current state of the art on the applications of cinchona alkaloids and their derivatives as chiral catalysts in the enantioselective nucleophilic addition of prochiral C¼O and C¼N bonds is discussed. The schemes exemplified in this chapter demonstrate the indispensable role of cinchona alkaloids as catalysts in these important research areas.

show abstract

“…It also promotes the 1,3-cycloaddition Desymmetrization. 7 (9R)-9-Amino-9-deoxyquinidine was an efficient and highly enantioselective catalyst for the intramolecular aldolization of symmetrical 4-substituted-2,6-heptanediones (eq 5). (R)-celery ketone 91% ee (5) Asymmetric Hydrogenation.…”

Section: Asymmetric Reactions Of αβ-Unsaturatedmentioning

confidence: 99%