Direct amidation of unprotected amino acids using B(OCH<sub>2</sub>CF<sub>3</sub>)<sub>3</sub>
作者:Rachel M. Lanigan、Valerija Karaluka、Marco T. Sabatini、Pavel Starkov、Matthew Badland、Lee Boulton、Tom D. Sheppard
DOI:10.1039/c6cc05147b
日期:——
A commercially available borate ester, B(OCH2CF3)3, can be used to achieve protecting-group free direct amidation of [small alpha]-amino acids with a range of amines in cyclopentyl methyl ether. The method can...
Bio-Inspired Dimerization Reaction of Tryptophan Derivatives in Aqueous Acidic Media: Three-Step Syntheses of (+)-WIN 64821, (−)-Ditryptophenaline, and (+)-Naseseazine B
作者:Shinji Tadano、Yuri Mukaeda、Hayato Ishikawa
DOI:10.1002/anie.201303143
日期:2013.7.29
Doubling up: The direct bio‐inspired dimerization of commercially available amine‐free tryptophanderivatives in aqueousacidicmedia provides C2‐symmetrical and nonsymmetrical dimeric compounds. Further processing completes the concise syntheses of naturally occurring dimeric diketopiperazine alkaloids such as (+)‐WIN 64821 (see picture) in overall yields of up to 20 %.