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Intrinsically safe and shelf stable diazo transfer reagent for fast synthesis of diazo compounds

At the Scientific Update OPRD conference in Milan earlier this month, Xiaohu Deng from Kura Oncology discussed a pyrimidine-derived diazo intermediate that exists predominantly in the tautomeric ‘tetrazole’ form at equilibrium in solution.[1] The compound was shown as a putative retrosynthetic building block for synthesis of a J&J P2X7 antagonist (Figure 1).[2] I’d not come

You really wouldn’t have wanted to get sick in the 1900’s…..

Antibacterial chemotherapy before the turn of the nineteenth century really was a brutal business. A fine line between killing bacteria or the host organism- the human population. Mercury and bismuth based ointments and elixirs were available from apothecaries and administered by quack doctors as remedies, most notably for syphilis- a sexually transmitted bacterial infection caused

A concise total synthesis of Quinine and analogues via C-H activation

                    The naturally occurring cinchona alkaloids, and Quinine in particular, have been of interest to synthetic chemistry practitioners for many years, due ostensibly to its antimalarial activity, particularly against resistant strains of the disease. The original synthesis, by Woodward and Doering in 1944 was heralded as

The Chichibabin amination reaction

         2-Aminopyrides are useful synthetic intermediates and pharmacophores in a number of drugs.[1] The Chichibabin reaction, developed in the 1900’s gives a direct method for the amination of pyridine and pyridine derivatives (azines and azoles) using sodium or potassium amides. Intramolecular amination reactions are also known. The reaction can be run either

Antibiotics, synthetic organic chemistry and the war against the microbes:

One of the first encounters I had with complex structures and challenging organic synthesis was a course I took on the synthesis of antibiotics as an undergraduate chemist at Bath university almost thirty years ago. These molecules and I had had a love hate relationship for much of my early childhood, having consumed what must

Cyanomethylene trimethylphosphorane (CMMP)- a safer reagent for Mitsunobu couplings

The Mitsunobu reaction is a powerful coupling method for alkylation of various nucleophiles (H-A) with alcohols (R-OH).[1] The classical conditions use a redox system comprising of an azodicarboxylate (such as diethylaziodicarboxylate, DEAD) and a phosphine (normally triphenylphosphine, TPP). The alcohol is essentially activated in situ and coupling occurs with the generation of the phosphine oxide

Bio-Transforming: Stereodivergent cyclopropanation of non-activated alkenes  

One of the challenges associated with biocatalysis is the resulting stereochemistry is not always easy to predict and more often than not gives the unwanted isomer. The problem is compounded if the substrate has limited steric or electronic components to aid stereocontrol. A way around this problem is to engineer the wildtype protein. A resent

Protecting group free radical C-H trifluoromethylation of peptides  

The resurgence of peptide and protein-based therapeutics and the demand for chemical probes to elucidate complex biological pathways has driven the development of synthetic chemistry compatible with post translational modification and/or bioconjugation. The use of fluorine-modified biomolecules has enabled the 19F nucleus to be used in NMR experiments to study protein structure, dynamics and protein-ligand

Biocatalytic oxidation and synthesis of Esomeprazole

Esomeprazole is a proton pump inhibitor developed by Astra Zeneca in 2001 and marked under the trade name Nexium. Esomeprazole is the S-enantiomer of omeprazole (the racemate) and is an example of the controversial so-called “chiral switch” in with single isomers are developed and marked as having improved pharmacodynamic or phmacokinetic properties over the originally