Chromium arene complexes tricarbonyl deprotonation

A synthetically very powerful property of chromium tricarbonyl arene complexes is the ability to stabilize a negative charge at both the a- and /3 -positions of an alkyl side-chain. Deprotonation of the benzylic position using sodium hydride, f-butyl lithium, or potassium f-butoxide followed by addition of an electrophile affords alkylated products. The... 

Arene-chromium tricarbonyl complexes are electron-deficient aromatic species. They are readily deprotonated and are easily attacked by nucleophiles. 

Chiral benzylic amines have been synthesized from an optically pure arene tricarbonyl chromium complex via a stereoselective deprotonation/alkylation step (Scheme 35). 

Asymmetric reaction of the sulfides bearing a tricarbonyl(ri -arene)chromi-um complex was shown to be successful by Gibson and Simpkins [48,49]. The benzyhc methylene groups in tricarbonyl(ri -phenylmethyl alkyl sulfide)chro-mium(O) and tricarbonyl(ri -l,3-dihydroisobenzothiophene)chromium(0) were highly asymmetrically functionahzed by deprotonation with a chiral bis-Uthium amide and subsequent electrophihc reactions (Tables 4 and 5). 

NFSi as an Oxidizing Reagent. It has been demonstrated that the benzylic position of arene chromium tricarbonyl complex could be deprotonated by strong bases and the resulting anion... 

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