The synthesis of bioactive indolocarbazoles related to K-252a.
A range of functionalised indolocarbazoles, related to the natural product K-252a, have been prepared, starting from a readily available bridged cyclopentene. Sequences of transformations, involving initial hydroboration-oxidation to give a ketone, or by dihydroxylation and cyclic sulfate formation, enable the preparation of diverse indolocarbazole products. Issues of imide nitrogen protection for the indolocarbazole, and opportunities for asymmetric desymmetrisation of key intermediates were also explored. A novel chiral lithium amide base mediated transformation of a cyclic sulfate intermediate gave the anticipated ketone product in up to 87% ee. A number of compounds, in the form of unprotected imide substituted indolocarbazoles, were screened for biological activity and were found to be potent inhibitors of a number of kinase enzymes.
Moffat
David
D
Celltech Therapeutics Ltd, 216 Bath Road, Slough, SL1 4EN, UK.
Nichols
Christopher J
CJ
Riley
Dean A
DA
Simpkins
Nigel S
NS
D002227:Carbazoles / Q000138:chemical synthesis* / Q000494:pharmacology*; D003517:Cyclopentanes; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D026121:Indole Alkaloids; D047908:Intracellular Signaling Peptides and Proteins; D047428:Protein Kinase Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D000099190:MAP-Kinase-Activated Kinase 2
D002227:Carbazoles; D003517:Cyclopentanes; D066246:ErbB Receptors; D026121:Indole Alkaloids; D047908:Intracellular Signaling Peptides and Proteins; D047428:Protein Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D000099190:MAP-Kinase-Activated Kinase 2; C049985:staurosporine aglycone