863870-76-2Relevant academic research and scientific papers
Experimental and computational study of the 1,5-o → n carbamoyl snieckus-fries-type rearrangement
Feberero, Claudia,Lopez, Carlos Silva,Sanz, Roberto,Sedano, Carlos,Suarez-Pantiga, Samuel
, p. 12561 - 12578 (2020/11/09)
The reactions of o-lithiated O-aryl N,N-diethylcarbamates with different C-N multiple bond electrophiles have been thoroughly studied. A 1,5-O → N carbamoyl shift, a new variation of the anionic Fries-type rearrangement, takes place when nitriles, imines, or alkylcarbodiimides are employed. In these cases, the carbamoyl group plays a dual role as a directing group, building up a variety of functional groups through the 1,5-O → N carbamoyl migration. On the other hand, the use of iso(thio)cyanates and arylcarbodiimides led to non-rearranged o-functionalized Oarylcarbamates. This reactivity was further computationally explored, and the governing factor could be traced back to the relative basicity of the alternative products (migrated vs nonmigrated substrates). This exploration also provided interesting insights about the degree of complexation of the lithium cations onto these substrates. A new access to useful 2-hydroxybenzophenone derivatives has also been developed.
A new and efficient synthesis of 4-functionalized benzo[6]furans from 2,3-dihalophenols
Sanz, Roberto,Castroviejo, M. Pilar,Fernandez, Yolanda,Fananas, Francisco J.
, p. 6548 - 6551 (2007/10/03)
Tandem Sonogashira coupling/5-endo-dig cyclization reactions on 2,3-dihalophenols suppose a straightforward entry to 4-halobenzo[b]furans, which can be easily transformed into 4-functionalized benzo[b]furans, that are difficult to synthesize by other proc
