Use of F-BODIPYs as a protection strategy for dipyrrins: optimization of BF(2) removal

J Org Chem. 2012 Apr 6;77(7):3439-53. doi: 10.1021/jo3002003. Epub 2012 Mar 9.

Abstract

We recently reported the first general method for the deprotection of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes (F-BODIPYs) involving a microwave-assisted procedure for the removal of the BF(2) moiety, and liberation of the corresponding free-base dipyrrin. Further optimization of the reaction has resulted in a more convenient and accessible protocol. The availability of this new methodology enables BF(2)-complexation to be used as a dipyrrin protection strategy. Herein lies a detailed examination of the deprotection reaction, with a view to optimization and gaining mechanistic insight, and its application in facilitating a multistep synthesis of pyrrolyldipyrrins.