The Journal of Organic Chemistry
The directing ability of the methylthio substituent in lithiation reactions of thiophenes
EC Taylor, DE Vogel
Index: Taylor, Edward C.; Vogel, Dennis E. Journal of Organic Chemistry, 1985 , vol. 50, # 7 p. 1002 - 1004
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Citation Number: 42
Abstract
An important method for a-functionalization of thiophenes is lithiation followed by treatment with an electrophile.'When a coordinating substituent (ie,(dimethy1amino) methyl) is present in position 3, lithiation is directed to the 2-p0sition,~ whereas noncoordinating sterically bulky substituents in position 3 (Le., tert-butyl) lead exclusively to 5-lithiati0n.~ When the coordinating ability of a 3-substituent does not fully compensate for steric effects, lithiation ...