Synlett 2009(13): 2203-2204  
DOI: 10.1055/s-0029-1217623
SPOTLIGHT
© Georg Thieme Verlag Stuttgart ˙ New York

DABAL-Me3: A Versatile Methylating Agent

Abhishek Goswami*
Natural Products Chemistry Division, North-East Institute of Science & Technology, Jorhat-785 006, Assam, India
e-Mail: abhijrt@yahoo.com;
Further Information

Publication History

Publication Date:
23 July 2009 (online)

Introduction

DABAL-Me3 is a very suitable, easy to use reagent to ­methylate a variety of functional groups like aldehydes, imines, enones, amides, etc. Although trimethyl aluminium has been traditionally used as a methylating agent, its pyrophoric nature stands as a major obstacle in its sustainability. Several other Me3Al˙NR3 species such as Me3Al˙pyridine, Me3Al˙TMEDA (tetramethyletyhylenediamine) are also reported, but they are too reactive to be used under normal laboratory conditions. DABAL-Me3, which is actually a 2:1 complex of Me3Al and DABCO, is free from these shortcomings as it can be manipulated without the need for an inert atmosphere. [¹] [²]

DABAL-Me3 can be prepared by adding neat AlMe3 to freshly sublimed DABCO in toluene at 0 ˚C. The white precipitate is separated from toluene and washed several times with diethyl ether. [³] The versatility of the reagent can be easily assessed by its capability to methylate a wide variety of substrates.

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