Absolute stereochemistry assignment of N-phosphorylimine-derived aza-Diels-Alder adducts with TDDFT CD calculations.
N-phosphorylimines undergo Lewis acid-catalyzed Diels-Alder reactions with Danishefsky's diene. Application of the chiral catalyst zinc(II)-(S)-BINOL results in good-to-low asymmetric induction but poor chemical conversion. However, the absolute stereochemistry of novel aza-Diels-Alder cycloadducts, such as diethyl 4-oxo-2-phenyl-3,4-dihydropyridin-1(2H)-ylphosphonate, can be determined using circular dichroism (CD). Comparison between experimental and TDDFT-calculated CD spectrum shows that use of the (S)-catalyst results in predominant formation of the (6R) cycloadducts.
Di Bari
Lorenzo
L
Dipartimento di Chimica e Chimica Industriale, Pisa, Italy.
Guillarme
Stéphane
S
Hermitage
Stephen
S
Jay
David A
DA
Pescitelli
Gennaro
G
Whiting
Andrew
A