10.1016/j.tet.2012.04.016
The research focuses on the development of an efficient and environmentally friendly method for the preparation of aromatic esters from aromatic bromides and aromatics, which are important building blocks in the pharmaceutical and agrochemical industries. The study presents a novel one-pot conversion method that does not require transition metals or carbon monoxide, addressing the drawbacks of previous methods that involved expensive catalysts, toxic gases, and complex operational procedures. The process involves the treatment of aromatic bromides with n-BuLi, followed by reaction with either ethyl formate or DMF, and finally with molecular iodine in the presence of K2CO3 and an alcohol. The researchers found that this method could effectively convert various aromatic bromides into aromatic ethyl and methyl esters in good yields. The chemicals used in this process include aromatic bromides, n-BuLi, ethyl formate, DMF, molecular iodine, and K2CO3, along with different alcohols such as ethanol and methanol. The conclusions of the research emphasize the effectiveness of the new method in providing a transition-metal-free, carbon-monoxide-free route for the synthesis of aromatic esters.
10.1016/j.tet.2008.09.070
The research aims to develop a concise and stereoselective method for synthesizing azepines, which are important heterocyclic compounds. The study employs the conjugate addition of formamides to nitroalkenes, followed by an intramolecular nitrile oxide cycloaddition (INOC) reaction to achieve this goal. Key chemicals used include formamides, nitroalkenes, tBuOK (potassium tert-butoxide), phenyl isocyanate, and ethyl formate. The researchers observed high cis-selectivity in the formation of azepines and successfully developed a one-pot procedure for the synthesis, achieving moderate yields. The formyl group in the synthesized compounds could be readily removed under acidic conditions without significant epimerization, yielding N–H azepines. The study concludes that this method provides a useful and stereoselective route for preparing azepines from readily available starting materials, with potential applications in the synthesis of aza-heterocyclic compounds.