Copper-catalyzed cascade aminoalkynylation–oxidation of propargylic alcohols has been realized, sterospecifically providing an array of (Z)-2-amino conjugated enynals/enynones in good yields under mild conditions. This transformation involves a rare 1,3-alkynyl migration of propargylic alcohols and simultaneously forms C–C, C–N, and C═O bonds. Furthermore, (Z)-2-amino conjugated enynals were applied
Long wavelength heteroaryl-substituted dipyrrometheneboron difluoride
申请人:Molecular Probes, Inc.
公开号:US05248782A1
公开(公告)日:1993-09-28
This invention describes novel 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes containing heteroaryl substituents conjugated to the fluorophore and methods for their synthesis. The heteroaryl substituted compounds (heteroaryl dyes) generally have the structure: ##STR1## wherein any or all of the substituents R.sub.1 -R.sub.7, but at least one of such substituents, is a heteroaryl group, including 5- or 6-member rings, singly or fused, containing one or more heteroatoms. The new dyes that have spectral properties that are significantly shifted from those of the parent alkyl-substituted dyes, usually accompanied by an increase in photostability and in some cases by an increase in the extinction coefficient relative to the alkyl-substituted dyes. The general method of synthesis includes formation of pyrromethene salt intermediates followed by cyclization with boron trifluoride in the presence of a base to give heteroaryl-substituted dipyrrometheneboron difluoride dyes.
Abstract Novel 5,6,5,6-tetracyclic pyrazine/pyrrole-fused unsymmetric bis(BF2) fluorescentdyes (BOPYPYs) were obtained by reaction of pyrrole-2-carboxaldehyde with 1-(pyrazin-2-yl)hydrazine in the presence of Et3N-BF3·Et2O for the first time. The absorption maxima of pyrazine-fused BOPYPY are obviously bathochromic shifts, in contrast to those of the reported BOPPY, indicating that the discrepant
Unsymmetrical BODIPY dyes carrying four aryl moieties in positions 1, 3, 5, and 7 can be assembled in a modular fashion from pyrrole building blocks individually produced in two separate [6π] electrocyclizations. The method uses benzaldehydes, acetophenones, and glycine nitrile or glycine ethyl ester as the starting materials.