Biomimetic Catalytic Retro-Aldol Reaction Using a Cation-Binding Catalyst: A Promising Route to Axially Chiral Biaryl
Sushovan Paladhi1,2, Si Joon Park1, In-Soo Hwang1
1Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea.
Organic Letters
|April 13, 2023
Summary
Researchers developed a biomimetic catalytic retro-aldol reaction using a novel chiral catalyst. This method efficiently produces highly enantiomerically enriched aldols and valuable axially chiral aldehydes from simple precursors.
Area of Science:
- Organic Chemistry
- Catalysis
- Biomimetic Chemistry
Background:
- The retro-aldol reaction is crucial for synthesizing carbonyl compounds.
- Developing enantioselective catalysts for retro-aldol reactions remains a challenge.
- Type-II aldolases offer inspiration for catalytic strategies.
Purpose of the Study:
- To develop a biomimetic catalytic retro-aldol reaction.
- To utilize a chiral oligoEG cation-binding catalyst as a type-II aldolase mimic.
- To achieve rapid access to enantiomerically enriched aldols and chiral aldehydes.
Main Methods:
- Employing a chiral oligoEG cation-binding catalyst.
- Investigating the retro-aldol reaction of racemic α-substituted β-hydroxy ketones.
- Optimizing reaction conditions for selectivity and yield.
Main Results:
- The biomimetic protocol rapidly produced highly enantiomerically enriched aldols.
- A selectivity factor (s) of up to 70 was achieved.
- The synthetic strategy proved feasible for accessing diverse axially chiral aldehydes.
Conclusions:
- The developed catalyst effectively mimics type-II aldolase activity.
- This approach provides efficient access to valuable chiral building blocks.
- The methodology holds promise for asymmetric synthesis applications.
Related Concept Videos
00:57C–C Bond Cleavage: Retro-Aldol Reaction
6.0K
The reverse of the aldol addition reaction is called the retro-aldol reaction. Here, the carbon–carbon bond in the aldol product is cleaved under acidic or basic conditions to form two molecules of carbonyl compounds. The mechanism of the reaction consists of three steps.
In the first step, as depicted in Figure 1, the base deprotonates the β-hydroxy ketone at the hydroxyl group to form an alkoxide ion.
In the first step, as depicted in Figure 1, the base deprotonates the β-hydroxy ketone at the hydroxyl group to form an alkoxide ion.
6.0K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.4K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.4K
01:08Base-Catalyzed Aldol Addition Reaction
3.6K
As depicted in Figure 1, base-catalyzed aldol addition involves adding two carbonyl compounds in aqueous sodium hydroxide to form a β-hydroxy carbonyl compound.
3.6K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
7.8K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
7.8K
01:15Acid-Catalyzed Aldol Addition Reaction
2.7K
The aldol reaction of a ketone under acidic conditions successfully forms an unsaturated carbonyl as the final product instead of an aldol. The acid-catalyzed aldol reaction is depicted in Figure 1.
2.7K
01:22Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
4.2K
Baeyer–Villiger oxidation converts aldehydes to carboxylic acids and ketones to esters. The reaction uses peroxy acids or peracids and is often catalyzed by acid. The reaction is named after its pioneers, Adolf von Baeyer and Victor Villiger. The reaction is achieved by a wide range of peracids such as m-chloroperoxybenzoic acid (mCPBA), perbenzoic acid (C6H5COOOH), peracetic acid (CH3COOOH), hydrogen peroxide (H2O2), and tert-butyl hydroperoxide (t-BuOOH).
The carbonyl center is...
The carbonyl center is...
4.2K