Compounds of formula (I): ##STR1## (wherein: l is 2-4; A and B are oxygen or sulfur; one of R.sup.1 and R.sup.2 represents a long chain alkyl, alkylcarbamoyl or aliphatic acyl group and the other of R.sup.1 and R.sup.2 represents a group of formula (III) or (II.sub.f): ##STR2## in which E represents a single bond, a bivalent heterocyclic group or a group of formula --CO--, --COO-- or --CONR.sup.6 --, where R.sup.6 is hydrogen or an imino-protecting group; m is 0-3; n is 0-10; q is 0 or 1; R.sup.4 is optionally protected hydroxy, mercapto group or carboxy; Q is an amino or nitrogen-containing heterocyclic group; R.sub.f.sup.4 R.sub.f.sup.5 and R.sub.f.sup.6 are independently selected from the group consisting of hydrogen atoms and C.sub.1 -C.sub.6 alkyl groups, or R.sub.f.sup.4 and R.sub.f.sup.5 or R.sub.f.sup.4, R.sub.f.sup.5 and R.sub.f.sup.6, together with the nitrogen atom to which they are attached, form a heterocyclic ring) are PAF antagonists which may be used to treat asthma, hypotension, inflammation and shock. They may be prepared by reacting the corresponding compound having a haloalkyl phosphate ester or alkylenephosphate ester group in place of the ammonioalkyl phosphate ester group with an appropriate amine.
Access to enantioenriched 2,3- and 2,5-dihydrofurans with a fully substituted C2 stereocenter by Pd-catalyzed asymmetric intermolecular Heck reaction
作者:Gustavo M. Borrajo-Calleja、Vincent Bizet、Thomas Bürgi、Clément Mazet
DOI:10.1039/c5sc01460c
日期:——
A palladium catalyzed intermolecular asymmetric Heck reaction provides access to valuable 2,3- and 2,5-dihydrofurans with a fully substituted C2 stereocenter with high levels of regio- and enantiocontrol.