Synthesis of DNA-Interactive Pyrrolo[2,1-<i>c</i>][1,4]benzodiazepines by Employing Polymer-Supported Reagents: Preparation of DC-81
作者:Ahmed Kamal、K. Reddy、V. Devaiah、N. Shankaraiah
DOI:10.1055/s-2004-834821
日期:——
generation of combinatorial library of substituted pyrrolo[2,1-c][1,4]benzodiazepine derivatives that provides a clean and efficient preparation and does not require conventional purification techniques like chromatography. This methodology involves intra molecular aza-Wittig reaction and has been extended for the synthesis of the naturalproduct DC-81 in good overall yields.
An efficient method for the reduction of aromatic azides in both solution and solid-phase has been developed by employing (BF3OEt2)-O-./EtSH. This report also describes resin cleavage employing this reagent system. Further, this protocol has been utilized for the solution as well as the solid-phase synthesis of pyrrolo[2, 1-c][1,4]benzodiazepines, including the naturally occurring antibiotic DC-81 and fused [2,1-b]quinazolinones. (c) 2006 Elsevier Ltd. All rights reserved.
Catalytic Staudinger/Aza-Wittig Sequence by in situ Phosphane Oxide Reduction
作者:Henri A. van Kalkeren、Colet te Grotenhuis、Frank S. Haasjes、C. Rianne A. Hommersom、Floris P. J. T. Rutjes、Floris L. van Delft
DOI:10.1002/ejoc.201300585
日期:2013.11
A Staudinger/aza-Wittig reaction sequence is described that is catalytic in phosphorus. Towards this end, the phosphaneoxide is reduced in situ by diphenylsilane, which allows for substoichiometric amounts of the catalyst 5-phenyldibenzophosphole to be used. The substrate scope is investigated and benzoxazoles, benzodiazepine imidates and a 2-methoxypyrrole were successfully synthesized. These investigations
A selective and facile method for the reduction of aromatic azides to amines by employing borontrifluoride diethyl etherate and sodium iodide. This methodology has been applied towards the preparation of biologically important imine-containing pyrrolobenzodiazepines and their dilactams through intramolecular reductive-cyclization process. In this protocol the reagent systems are amenable for the generation