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1,6‐Conjugate Additions of Carbon Nucleophiles to 2‐[(1 E ,3 E )‐4‐Arylbuta‐1,3‐dien‐1‐yl]‐4 H ‐chromen‐4‐ones
Author(s) -
Albuquerque Hélio M. T.,
Santos Clementina M. M.,
Balanay Mannix P.,
Cavaleiro José A. S.,
Silva Artur M. S.
Publication year - 2017
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201700944
Subject(s) - chemistry , nitromethane , malononitrile , nucleophile , pyrazole , medicinal chemistry , reactivity (psychology) , diethyl malonate , conjugate , indazole , nucleophilic addition , adduct , dabco , stereochemistry , organic chemistry , catalysis , mathematical analysis , mathematics , medicine , alternative medicine , pathology
The 1,6‐conjugate addition of nitromethane to 2‐[(1 E ,3 E )‐4‐arylbuta‐1,3‐dien‐1‐yl]‐4 H ‐chromen‐4‐ones was accomplished and led mainly to the corresponding β‐(nitromethyl)chromones. ( E )‐5′‐(Nitromethyl)‐3′‐styryl‐[1,1′‐biphenyl]‐2‐ol and 3′‐aryl‐2′‐nitro‐5′‐(nitromethyl)spiro[chromane‐2,1′‐cyclohexan]‐4‐one derivatives were also isolated as minor products from tandem processes, which result from the addition of a second molecule of nitromethane. The nucleophile scope was investigated with malononitrile, acetylacetone, ethyl cyanoacetate, and diethyl malonate, which gave the expected 1,6‐addition products; in the last case, it was also possible to isolate a minor product formed through a 1,8‐/1,6‐addition sequence. Computational calculations provided a rationale for the experimental reactivity of carbon nucleophiles with 2‐[(1 E ,3 E )‐4‐arylbuta‐1,3‐dien‐1‐yl]‐4 H ‐chromen‐4‐ones. The further functionalization of some adducts allowed the preparation of new nitrogen‐containing heterocyclic compounds, such as new styrylpyrrolidines and new pyrazole and bis(pyrazole) derivatives.