How does the Suzuki coupling reaction work?

The Suzuki coupling is a cross-coupling reaction used to form new carbon-carbon bonds between an aryl or vinyl boronic acid and an aryl or vinyl halide catalyzed by a palladium complex. 

The Suzuki coupling reaction couples aryl halides and arylboronic acids to form biaryl compounds. This versatile C-C bond forming reaction has been widely studied to expand its scope and improve efficiency.

Various catalytic systems have been explored, including photocatalytic coupling using palladium catalysts, Suzuki-Miyaura coupling of fluoroarenes, and nickel-catalyzed variants as a more earth-abundant option. Solvent selection and greener processing conditions have also been evaluated.

These diverse Suzuki coupling approaches have enabled numerous applications from protein modification to the synthesis of complex polyaromatic structures. Ongoing work continues to optimize Suzuki coupling for different substrates and reaction conditions to enhance the sustainability, efficiency, and selectivity of this important cross-coupling reaction.

The key steps are:

1. Oxidative addition - The palladium catalyst undergoes oxidative addition with the aryl/vinyl halide, inserting itself between the carbon-halogen bond. This forms an organopalladium complex.

2. Transmetalation - The organopalladium complex then undergoes transmetalation with the boronic acid, replacing the halide with an aryl/vinyl group from the boronic acid. This forms a new organopalladium complex.

3. Reductive elimination - Reductive elimination of the palladium catalyst from the complex then occurs, forming the new carbon-carbon bond between the two aryl/vinyl groups originally from the halide and boronic acid. The active palladium catalyst is regenerated. 

The Suzuki reaction works well for joining aryl or vinyl units together efficiently under relatively mild conditions. It requires a base, usually an aqueous hydroxide, to activate the boronic acid. 

The Suzuki coupling is a very useful tool in organic synthesis and pharmaceutical research for building biaryls and styrenes.

Beta-lactams

Beta-lactams are an essential antibiotic drug class produced by both fermentation and synthetic methods. Their unique reactivity enables the generation of novel compounds for pharmaceutical applications.

Beta-lactams are an important class of compounds in biological and synthetic chemistry. They are commonly used as antibiotics to treat bacterial infections. Beta-lactams work by inhibiting penicillin-binding proteins that are crucial for bacterial cell wall biosynthesis. Most beta-lactams are produced by fermentation or modification of fermented intermediates, except for carbapenems and aztreonam which require synthetic routes.

The reactivity of the beta-lactam ring has been widely studied, making it a useful substrate in synthetic organic chemistry. The ring can be opened through various reactions to generate new biologically relevant compounds. Efficient synthesis of new beta-lactams can be achieved from amidines using promoters like bismuth, indium, and copper salts. Diverse C4-N-substituted beta-lactams can also be prepared by nucleophilic reactions. A commonly used method in beta-lactam chemistry is the Ketene-Imine Staudinger Reaction.

Bibliography:

Zerong, Daniel, Wang. (2023). The Chemistry and Biology of Beta-Lactams.   doi: 10.1201/9781003330288

(2023). Enzymatic biosynthesis of β-lactam antibiotics.   doi: 10.1016/b978-0-443-19059-9.00007-4

Japheth, O., Ombito, and, Girija, S., Singh. (2019). Recent Progress in Chemistry of β-Lactams. Mini-reviews in Organic Chemistry,  doi: 10.2174/1570193X15666180914165303

Bimal, K., Banik., Alberto, Boretti. (2021). Hypotheses for synthesis of novel chiral beta-amino-beta-lactams through amidines.   doi: 10.1016/J.RECHEM.2021.100158

Rajneesh, Kaur., Divya, Tripathi., Kuldeep, Singh., Raman, Singh. (2018). Recent advances in β-lactam chemistry.  J. Integr. Sci. Technol., 2018, 6(2), 46-51

Adrian, Saura-Sanmartin., Laura, Andreu-Ardil. (2023). Stereoselective synthesis of β-lactams: recent examples.. Organic and Biomolecular Chemistry, 21(16):3296-3306. doi: 10.1039/d3ob00309d

Anusandhan National Research Foundation Act 2023

 

Anusandhan National Research Foundation Act 2023

An Act to provide for the registration and regulation of a financially research ecosystem, and open scientific research activities for the private sector in the India in accordance with the National Education Policy guideline.
Enacted by	Parliament of India
Assented to	15 August 2023
Commenced	1 December 2023
Bill citation	No. 25 2023
Status: In force (5th Feb 2024)

https://dst.gov.in/sites/default/files/NRF.pdf