Phenoxy function

Compounds of empirical formula M(OR) and LxM(OR)y, where R is an alkyl or aryl group, Lx represents a combination of other ligands, which may be either neutral or anionic, and n and y are integers >1, are the subjects of this chapter. Excluded from consideration are catecholates and semiquinones, and chelated ligands containing alkoxy or phenoxy functionalities, e.g. compounds derived from the ligand formed by deprotonation of 2-hydroxypyridine. 

Scheme 8.6 Preparation of S-PC-S triblock copolymer using phenoxy functional PS prepared using NMRP as a chain-stopper in the PC process...

A number of non-oxovanadium(IV) complexes have been generated by Schiff base ligands containing 02N donor sets. To date all the structurally characterized complexes contain two alkoxy or phenoxy functionalities and one imine-type functionality (48),316 617 618 The effects on varying substituents on the phenoxo groups have been investigated.620 The structure of bis[sali-cylaldehyde-2-hydroxyanilinato(2-)]VlV,316 shows the vanadium to have a nearly octahedral coordination environment. 

B] Coupling Reactions. The coupling reaction is defined as— An electrophilic substitution reaction involving the diazonium ion that eventually reacts at the position of greatest electron availability, i.e., the position either ortho-or para-to the electron releasing amino or phenoxy functions . 

How does a diazotized entity gets coupled with an amine or a phenoxy function ... 

Similarly to mono-phenoxy-NHCs, Shen used a bis(phenoxy)-functionalized NHC ligand to obtain lanthanide complexes in a deprotonation reaction with LiM[N(i-Pr)2]4(THF) and n-BuLi in a 2 1 2 molar ratio in THE In this case the solvents used had a significant effect on the solid-state structure of the complexes obtained. Anionic [ML2][Li(DME3)] (M = Sm, Er, Yb L = l,3-bis[0-4,6-di-t-Bu-C6H2-2-CH2][C N(CHCH)N ]) 28 were obtained upon crystallization from DME-toluene and neutral [(THE)Li(p-L)SmL] 29, upon crystallization in THF-toluene... 

Herbicides can be grouped according to common stmctural features. Sometimes the assignment is arbitrary when there are a multitude of functional groups, eg, acifluorfen which is a diphenyl ether (phenoxy compound) as well as a trifluoromethyl compound. 

Compare the spin density surface for vitamin E radical to those of phenoxy and BHT radicals (see also Chapter 16, Problem 2). Are there significant differences among the three If so, elaborate. What is the function of the long alkyl chain in vitamin E Examine an electrostatic potential map for vitamin E radical. Do you expect it to be soluble in aqueous (polar) or non-aqueous (non-polar) environments, or both ... 

Functionalized 5-alkoxymethyl- and 5-phenoxymethyl-2(5//)-furanones 44-46 were obtained starting from 3-alkoxy- and 3-phenoxy-2-hydroxy ketones 40 (98T1801). Condensation of the hydroxy ketones 40 with a slight excess of diethyl malonate 41 (Z = COOMe R = Me), ethyl cyanoacetate 42 (Z = CN R = Me),... 

Even in solution the relative rigidity of the polymer support can play a significant role in the reactivity of attached functional groups. Contrasting studies conducted with chloromethylated derivatives of poly(arylene ether sulfone) (Tg 175°C), phenoxy resin (Tg= 65°C) and polystyrene (Tg= 105°C) allow evaluation of chain rigidity effects. We have shown that the rates of quaternization of chloromethylated poly(arylene ether sulfones) and phenoxy resin deviate from the anticipated second order process at... 

The synthesis of benzo[Z>]furan derivatives has become a very active field because these molecules have been recently identified as having a variety of biological activities. For example, they can function as inhibitors of protein tyrosine phosphatase IB with antihyperglycemic properties <00JMC1293>, as well as potent and short-acting p-blockers in the treatment of various cardiovascular diseases . An inexpensive, reusable clay has been utilized to catalyze a facile cyclodehydration under microwave without solvent to form 3-substituted benzo[2>]furans from substituted a-phenoxy acetophenones 104. One of the important features of this procedure is that all the selected cyclodehydration reactions are complete in less than 10 minutes <00SL1273>. 

Lallemand et al. have found a pericyclic-anionic domino three-component reaction to prepare highly functionalized alcohols.115931 This reaction was originally developed by Vaultier, Hoffmann et al.[59bl Diels-Alder reaction of a 1,3-dienylboronate with an acrylate yields a mixture of endo and exo diastereomers of the coupled allylboronate, which in the presence of an aldehyde such as 4-phenoxy-butyraldehyde undergoes an allylation reaction. After hydrolysis the resulting diastereomeric alcohols are obtained in about 50 % yield, whereby two new stereogenic centers are formed in a stereoselective fashion. 

When, furthermore, phenols (368) are coupled with 1 in the presence of a Pd° catalyst, the phenoxy-methyl-1,3-dienes 369 are produced [158]. As aryl allyl ethers, these can be made to undergo a Claisen rearrangement (205 °C, DMF) and the ensuing 2-(l,3-dienylmethyl)phenols 370 finally cydize in the presence of a trace of acid to a mixture of exo-methylene chromans 371 (major product) and dihydrobenzofur-ans 372 - a remarkable generation of functional and structural complexity from simple starting materials with 100% atom economy and underlining impressively the synthetic versatility of modern allene chemistry ... 

This group of pesticides comprises different families of chemicals with her-bicidal action including substituted phenols, chlorinated aliphatic acids, chloro-phenoxy alkanoic acids, and substituted benzoic acids, which possess carboxyl or phenolic functional groups capable of ionization in aqueous media to yield anionic species [47,151,168-170]. 

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