- Full text PDF available (2)
A novel aldehyde dual-linker system has been developed for the solid phase synthesis of sterically hindered amides. The linker [5-(4-formyl-3-hydroxyphenoxy)pentanoic acid] exploits an intramolecular oxygen-nitrogen acyl transfer mechanism to prepare compounds that are unattainable with current commercially available linkers. A dual linker system,… (More)
As a consequence of growing environmental awareness, it is now inappropriate to design a synthetic metal-mediated transformation that involves a noncatalytic use of toxic and expensive transition-metal species. One of the earliest examples of such a metal-mediated transformation is the Pauson-Khand reaction, a [2+2+1] cyclocarbonylation that generates a… (More)
Aims. To investigate several partially-erupting prominences to study their relationship with other CME-associated phenomena and to compare these observations with observables predicted by a model of partially-expelled flux ropes (Gibson & Fan, 2006a, b). Methods. We have studied 6 selected events with partially-erupting prominences using multi-wavelength… (More)
The syntheses and structures of three cyclophanes containing two (Z)-dehydrophenylalanine residues are reported; the length of the tethers between the two amino acid residues is easily altered and changing this parameter has a significant effect on the solid state structures of the cyclophanes.
Carbonylcobalt(0) species have been used as linkers between alkynes and a polymer support for the first time. The alkynes may be loaded indirectly onto a phosphine functionalised polymer via their hexacarbonyldicobalt(0) complex, or directly onto a cobalt coated polymer. The alkynes have been released either as alkynes, thus providing a traceless method of… (More)
Chiral base chemistry has been used to create three chiral centres in one pot on a C3-symmetric substrate. The potential of this new approach to C3-symmetric molecules is exemplified by the creation of an enantiopure C3v-symmetric triol, triphosphane and tripyridine. A ruthenium complex of the last compound has been studied by X-ray crystallography.
The conformationally constrained analogues of phenylalanine, tetrahydroisoquinoline-3-carboxylic acid (Tic), Sic, Hic and Nic, and the new amino acid Xic have been incorporated into a potent and highly selective cholecystokinin-2 (CCK(2)) receptor antagonist (2) in place of the phenylalanine residue, producing compounds 15a-e. High selectivities for CCK(2)… (More)
A chiral-base mediated reaction has been used to synthesise the polyethers illustrated and their enantiomers; CD spectroscopy revealed that the homochiral isomers A may be viewed as a C3-symmetric arrangement of fixed paddles while the heterochiral isomers B form a C3-symmetric arrangement of rotating paddles.