While thiocarbonyl-stabilised phosphonium ylides generally react upon flash vacuum pyrolysis by the extrusion of PhPS to give alkynes in an analogous way to their carbonyl-stabilised analogues, two examples with a hydrogen atom on the ylidic carbon are found to undergo a quite different process. The net transfer of a phenyl group from P to S gives ()-configured 1-diphenylphosphino-2-(phenylsulfenyl)alkenes in a novel isomerisation process via intermediate λ-1,2-thiaphosphetes. These prove to be versatile hemilabile ligands with a total of seven complexes prepared involving five different transition metals.
View Article and Find Full Text PDFThe prevalent occurrence of herbicide resistant weeds increases the necessity for new site of action herbicides for effective control as well as to relax selection pressure on the known sites of action. As a consequence, interest increased in the unexploited molecule cinmethylin as a new solution for the control of weedy grasses in cereals. Therefore, the mechanism of action of cinmethylin was reevaluated.
View Article and Find Full Text PDFWhile thermolysis of thiocarbonyl-stabilised phosphonium ylides generally results in extrusion of Ph(3)PS to give alkynes, those with a P=CH function instead undergo a novel P to S transfer of a phenyl group to give (Z)-configured 1-phosphino-2-sulfenylalkenes of interest as bidentate ligands.
View Article and Find Full Text PDFAzeotropic reflux chromatography (in which the eluent is continuously recycled by means of refluxing) was used to separate a mixture of spiroketal intermediates in the scale-up synthesis of spongistatin 1, leading to an improved separation and an approximately 35-fold reduction in the amount of solvent used.
View Article and Find Full Text PDFA series of small molecule orally bioavailable ghrelin receptor agonists have been identified through systematic optimisation of a high throughput screening hit.
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