Synthesis of highly hindered diphenyl ethers

Multiple Modes of Action of Diphenyl Ethers

Diphenyl ethers are the most versatile phytotoxic com pounds known so far with respect to their targets in the plant cell. According to their substituents, the following modes o f action can be found; (a) inhibition o f photosynthetic electron transport effective at two binding sites, (b) peroxidative activity (degradation o f cellular constituents), (c) inhibition o f carotenogenesis, (d) decr...

Cu-catalyzed arylation of phenols: synthesis of sterically hindered and heteroaryl diaryl ethers.

Cu-catalyzed O-arylation of phenols with aryl iodides and bromides can be performed under mild condition in DMSO/K(3)PO(4) with use of picolinic acid as the ligand for copper. This method tolerates a variety of functional groups and is effective in the synthesis of hindered diaryl ethers and heteroaryl ethers.

Enantioselective synthesis of hindered cyclic dialkyl ethers via catalytic oxa-Michael/Michael desymmetrization.

An asymmetric oxa-Michael/Michael cascade reaction of p-quinols and α,β-unsaturated aldehydes provides access to hindered dialkyl ethers. A highly enantioselective oxa-Michael addition of a tertiary alcohol precedes an intramolecular cyclohexadienone desymmetrization, which allows for the concomitant formation of four contiguous stereocenters in a single step. The highly functionalized bicyclic...

Polybrominated Diphenyl Ethers in the Canadian Environment

Polybrominated diphenyl ethers in UK human milk

24 Fourteen tri-deca polybrominated diphenyl ethers (PBDEs) were investigated in 35 human 25 milk samples from Birmingham, UK. While none of the hepta-nona BDEs (the main 26 components of the OctaBDE technical mixture) were above the limit of quantitation (LOQ); 27 BDE-47 (average concentration = 3.3 ng g lipid weight (lw)) was quantified in all samples 28 contributing 34-74% to Σtri-hexa BDEs ...