81245-33-2Relevant academic research and scientific papers
REGIOSELECTIVE METALLATIONS OF (METHOXYMETHOXY)ARENES
Ronald, Robert C.,Winkle, Mark R.
, p. 2031 - 2042 (2007/10/02)
The methoxymethoxy substituent when attached to an aromatic ring functions as a moderately strong ortho-directing group in hydrogen-metal exchenge reactions.In many cases the propensity of the methoxymethoxylated arene toward ring metallations is greatly enhanced with concomitant suppression of undesirable side reactions such as nucleophilic attack and addition of metallating species.Unlike many other ortho-directing groups, the regio-direction of the methoxymethoxy substituent when in conjunction with other weaker directing groups is dependent upon the metallating medium.Thus, by changing the electron donating capacity of the metallating medium it is possible to selectively direct metallation to either of the positions ortho to the methoxymethoxy substituent.
Regioselective Metalation Reactions of Some Substituted (Methoxymethoxy)arenes
Winkle, Mark R.,Ronald, Robert C.
, p. 2101 - 2108 (2007/10/02)
The methoxymethoxy substituent acts as a relatively strong ortho-directing group in hydrogen-metal exchange reactions.However, the directing effects are influenced by the metalation medium, thus permitting an unusual degree of control of the site of metalation.In conjunction with weak ortho-directing groups, the metalation ortho to the methoxymethoxy group can be directed to either of the ortho positions by controlling the electron-donating capacity of the metalating solvent.In strongly donating solvents the 1,2,4-substitution pattern will arise from a meta-substituted methoxymethoxy arene, while in nondonating solvents the 1,2,3-substitution is favored.In addition, the methoxymethoxy group serves also to enhance the rate of metalation and to stabilize the aryl-metalated products so that some competing addition reactions are supressed.
