200064-39-7Relevant academic research and scientific papers
Regioselective reactions of 3,4-pyridynes enabled by the aryne distortion model
Goetz, Adam E.,Garg, Neil K.
, p. 54 - 60 (2013/02/23)
The pyridine heterocycle continues to play a vital role in the development of human medicines. More than 100 currently marketed drugs contain this privileged unit, which remains highly sought after synthetically. We report an efficient means to access di- and trisubstituted pyridines in an efficient and highly controlled manner using transient 3,4-pyridyne intermediates. Previous efforts to employ 3,4-pyridynes for the construction of substituted pyridines were hampered by a lack of regiocontrol or the inability to later manipulate an adjacent directing group. The strategy relies on the use of proximal halide or sulfamate substituents to perturb pyridyne distortion, which in turn governs regioselectivities in nucleophilic addition and cycloaddition reactions. After trapping of the pyridynes generated in situ, the neighbouring directing groups may be removed or exploited using versatile metal-catalysed cross-coupling reactions. This methodology now renders 3,4-pyridynes as useful synthetic building blocks for the creation of highly decorated derivatives of the medicinally privileged pyridine heterocycle.
Complex base-induced generation of 3,4-didehydropyridine derivatives: New access to aminopyridines or pyridones
Vinter-Pasquier, Karine,Jamart-Gregoire, Brigitte,Caubere, Paul
, p. 2113 - 2129 (2007/10/03)
The complex base, NaNH2-tert-BuONa, in THF easily transforms 3-bromopyridine and 2-pyridone derivatives into the corresponding hetarynes. The reaction of representative amines (dialkylamines, morpholine, piperidine) with these reactive intermediates leads to the preparation of aminopyridines in good yields and illustrates the synthetic usefulness of such reactions.
