| Popis: |
The oxidative-addition reaction between an arylmethyl chloride (RCH2Cl; R = 1-C10H7, 2,4,6-Me3C6H2, 4-MeC6H4, 3-MeC6H4, C6H5, 4-ClC6H4) and tin powder in boiling toluene produces bis(arylmethyl)tin dichlorides, [(RCH2)2SnCl2] in good yields. At 160 °C in mesitylene bis(1-naphthylmethyl)tin dichloride undergoes Sn-C homolytic cleavage to generate two 1-naphthylmethyl radicals (1-C10H7CH2•) which were trapped by TEMPO (C9H8NO•). Subsequently, the radicals (RCH2•) produced in this manner were utilized for efficient substitution reactions with electron-rich arenes (R'H; R' = 2,4,6-Me3C6H2, 1,2,4,5-Me4C6H, 1,2,3,4,5-Me5C6) to obtain a variety of unsymmetrical diarylmethanes (RR´CH2). The addition of one equivalent of iodine (I2) to the reaction mixture resulted in a significant increase in the yields of coupled products. |
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