33’-Disubstituted bisphenols

A detailed analysis of the 3, 3 -disubstituted bisphenol containing polycarbonates provided an explanation for their observed oxygen permeabilities. However such an approach is not of general utility. Using an existing free-volume approach, a qualitative... 

The intensive mechanistic studies of phenoxyl self-reactions proved a great variety of mechanisms and rate constants of these reactions [2,3,6], The substituents can dramatically influence the mechanism and kinetics of self-reactions. Due to free valence delocalization the phenoxyl radical possesses an excess of the electron density in the ortho- and para-positions. Mono- and disubstituted phenoxyls recombine with the formation of labile dimers that after enolization form bisphenols [3,6],... 

Synunetrically disubstituted molecules of type II are mostly obtained from bifunctional substrates such as bisphenols, cyclic urcids, etc., or bifiinctional amines such as ethylenediamine or piperazine. Accordingly, the amino group replacement of mono-functional Mannich bases by bifunctional nucleophiles such as nitroalkanes or bisamides gives derivatives of type II, as represented by the heat stabilizer for polymers 496, bearing two antioxidant phenolic moieties per molecule. 

Methacrylamide monomers were also considered (Scheme 2.2). 2-Metha-crylamidoethylphosphonic acid was prepared from the expensive (2-ami-noethyl)phosphonic acid in one step. Other monomers (Scheme 2.2, monomers 1 and 2) were synthesized from bisphenol A diglycidyl ether. The ring-opening of epoxides was achieved with aqueous ammonia at high temperature and pressure and the subsequent reaction with diethyl (2-bromoethyl)phosphonate led either to mono- or disubstituted product. Targeted monomers were finally obtained after (i) reaction with methacryloyl chloride and (ii) hydrolysis of the phosphonated ester groups. 

The introduction of ring strain as an aid to ROP was further supported by the attachment of diols to yield spirocycHc phosphazenes [56]. In these studies, 2,2 -bisphenol, 1,8-dihydroxynaphthalene, 1,8-diaminonaphthalene and catechol were found to readily attach in a geminal fashion (1,1-disubstituted) and, followed by treatment with sodium 2,2,2-trifluoroethoxide to remove remaining halide, yielded a stable trimer material (Figure 4.6). Additional structures formed exhibited 1,3 substitutions of selected bifunctional pendant groups, similar to that of the metal-locenyl derivatives (Figure 4.7). 

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