PROXIMITY EFFECT IN ARENE Pi-COMPLEX FORMATION
نویسندگان
چکیده
A proximity effect in arene ^-complex formation from the reaction system of an aryl G r i g n a r d reagent and anhydrous chromic chloride was investigated. The yields of arene ^-complexes and any accompanying reaction products were compared by the systematic variation of the aryl G r i g n a r d reagent employed. Phenyl G r i g n a r d gave the best yield of jr-complex followed by the benzyl, mesityl and /5-ethyl phenyl analogues. The styryl and phenylacetylenyl analogues did not form any ^-complexes. The coupling reaction of benzyl groups gave a new jr-complex, ?r-bibenzyl-;7r-toluene chromium, along with toluene, bibenzyl and trans-stilbene. 7Varas-stilbene was found without forming a trace amount of cis-stilbene. A mechanism for this stereospecific and a-hydrogen elimination coupling reaction is proposed.
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