Premium
Modular Bis(oxazoline) Ligands for Palladium Catalyzed Allylic Alkylation: Unprecedented Conformational Behaviour of a Bis(oxazoline) Palladium η 3 ‐1,3‐Diphenylallyl Complex
Author(s) -
Pericàs Miquel Angel,
Puigjaner Cristina,
Riera Antoni,
VidalFerran Anton,
Gómez Montserrat,
Jiménez Francisco,
Muller Guillermo,
Rocamora Mercè
Publication year - 2002
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20020916)8:18<4164::aid-chem4164>3.0.co;2-g
Subject(s) - oxazoline , palladium , enantiopure drug , tsuji–trost reaction , chemistry , allylic rearrangement , catalysis , alkylation , medicinal chemistry , stereochemistry , organic chemistry , enantioselective synthesis
New families of enantiopure bis(oxazolines) with 4,5‐ trans ( 5 a – g ) or 4,5‐ cis ( 6 c ) stereochemistry at the individual rings have been prepared in high yield. Their η 3 ‐allyl palladium complexes ( 8 a – g, 9 c and 10 ) have been used as catalytic precursors in allylic alkylation reactions with excellent enantioselectivities (up to 96 %) for the trans oxazoline derivatives, while Pd/ 6 c system was inactive. NMR studies on palladium η 3 ‐1,3‐diphenylallyl intermediates ( 11 a, c and e ) showed the presence of syn / syn ‐ and syn / anti ‐allyl isomers in solution; this resembles the first example of η 3 ‐ η 1 ‐ η 3 isomerism in Pd allylic complexes containing bis(oxazolines) derived from malonic acid.