Reagent choice

The processes described in this section should be contrasted with RAFT polymerization (Section 9.5.3), which can involve the use of similar thioearbonylthio compounds. A. A -dialkyl dithiocarbamates have very low transfer constants in polymerizations of S and (mctb)acrylatcs and arc not effective in RAFT polymerization of these monomers. However, /V,A -dialkyl dithiocarbamates have been successfully used in RAFT polymerization of VAc. Certain O-alkyl xanthates have been successfully used to control RAFT polymerizations of VAc, acrylates and S. The failure of the earlier experiments using these reagents and monomers to provide narrow molecular weight distributions by a RAFT mechanism can he attributed to the use of non-ideal reaction conditions and reagent choice. A two part photo-initiator system comprising a mixture of a benzyl dithiocarhamate and a dithiuram disulfide has also been described and provides better control (narrower molecular weight distributions).43... 

The Peterson reaction utilizes a metal derivative of chloromethyltrimethylsilane and the yields are better than the Wittig reaction. The intermediate P-hydroxysilanes can undergo either cis or trans elimination depending on reagent choice. 

The following section covers the general aspects of solvent losses by crud its formation and characteristics and its treatment and prevention. Losses attributed to emulsion and crud formation, can in part be related to (1) nature of feed (2) reagent choice (3) equipment selection and (4) method of operation, such as the droplet size, continuous phase, excessive turbulence, etc. 

A new concept for combinatorial experimentation has been completed. Whilst it aims at the synthesis of focused compound libraries and at selecting the right reagent choices to conduct synthesis, it organizes around the same scaleable process used throughout the chemical synthesis process. Within this concept, variations of... 

It should be noted that adipic acid use provides a level of flexibility in fuel and reagent choice and control level not available with other systems, and in site-specific cases, may prove to be much more economically advantageous than indicated above. 

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