Dichlorocarbene to Phenols Reimer-Tiemann Reactions

Despite the long history of the Reimer-Tiemann reaction, little has been reported in the phase transfer literature on this subject. There appears to be a single report of work in which phase transfer generated dichlorocarbene has been added to a phenolic substrate [58]. 4-Methyl-2,6-nonamethylenephenol reacts with dichlorocarbene in chloroform solution to yield the product of ortho insertion (76%) as shown in equation 2.39. The reactions of dichlorocarbene with several other lipophilic phenols are likewise reported [58]. 

Note also that use of chiral Z cra-hydroxyethyltrialkylammonium salts as catalysts led to optically active 1,1-dichlorocyclopropanes with the prochiral substrates styrene and trans-piopenyl benzene. While the degree of asymmetric induction was low, the feasibility of catalytic asymmetric induction in PTC reactions has certainly been demonstrated [12]. 

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