ortho-Oxo substituted trans 2,3-diaryloxiranes were regio- and stereoselectively arylated by arylzinc reagents, obtained from the corresponding boronic acids by B–Zn exchange. The reaction was quite general, irrespective to the aryl nucleophile and proceeded via a ring opening at the α-carbon with respect to the substituted aryl ring. The stereoselectivity was from high to complete toward the alcohol resulted from retention of configuration at the electrophilic carbon. The method allowed a direct and high yielding access to trans 2,3-diphenyl-2,3-dihydrobenzofuran, which is a key structural motif in resveratrol dimers as viniferins. The use of enantioenriched starting diaryloxiranes resulted in no loss of stereochemical integrity in the final trans 2,3-dihydrobenzofuran, which was characterized for the first time in enantioenriched form.
Regio- and Diastereoselective Organo-Zinc-Promoted Arylation of trans-2,3-Diaryloxiranes by Arylboronic Acids: Stereoselective Access to trans-2,3-Diphenyl-2,3-dihydrobenzofuran
D'Orsi R.;
2019-01-01
Abstract
ortho-Oxo substituted trans 2,3-diaryloxiranes were regio- and stereoselectively arylated by arylzinc reagents, obtained from the corresponding boronic acids by B–Zn exchange. The reaction was quite general, irrespective to the aryl nucleophile and proceeded via a ring opening at the α-carbon with respect to the substituted aryl ring. The stereoselectivity was from high to complete toward the alcohol resulted from retention of configuration at the electrophilic carbon. The method allowed a direct and high yielding access to trans 2,3-diphenyl-2,3-dihydrobenzofuran, which is a key structural motif in resveratrol dimers as viniferins. The use of enantioenriched starting diaryloxiranes resulted in no loss of stereochemical integrity in the final trans 2,3-dihydrobenzofuran, which was characterized for the first time in enantioenriched form.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
