Quinine-Catalyzed Asymmetric Synthesis of 2,2'-Binaphthol-Type Biaryls under Mild Reaction Conditions.
Simple quinine as an organocatalyst mediates the addition of various naphthols to halogenated quinones to afford non-C2 -symmetrical, axially chiral biaryl products, which are promising compounds as chiral ligands and organocatalysts. The rotational barrier required to have two distinct atropisomers has been evaluated in the products generated from the addition of naphthols to various quinones by means of DFT calculations and HPLC. The use of halogenated quinones as reagents was necessary to have configurationally stable enantiomeric products which can be obtained in good yield and stereoselectivity. These compounds have also been prepared in gram quantities and recrystallized to near enantiopurity.
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy.
Mauro
M
Moliterno
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy.
Riccardo
R
Cari
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy.
Antonio
A
Puglisi
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy.
Achille
A
Antenucci
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy.
Céline
C
Sperandio
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy.
Erica
E
Moretti
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy.
Antonio
A
Di Sabato
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy. riccardo.salvio@uniroma1.it.|IMC-CNR Sezione Meccanismi di Reazione, Università di Roma-Sapienza, P. le Aldo Moro 5, 00185, Roma, Italy. riccardo.salvio@uniroma1.it.
Riccardo
R
Salvio
Dipartimento di Chimica, Sapienza University of Roma, P. le Aldo Moro 5, 00185, Roma (I, Italy. marco.bella@uniroma1.it.
Marco
0000-0003-2223-6025
M
Bella
atropisomers; biaryls; chirality; density-functional calculations; organocatalysis