51689-55-5Relevant academic research and scientific papers
Steering of the Selectivity of Formation of Many-membered Oligomers by Template and Cesium Effects
Voegtle, Fritz,Ley, Fritz
, p. 3000 - 3002 (2007/10/02)
Cyclization of the bis(bromomethyl) compounds 1 and 2 with thioacetamide in the presence of carbonates M2CO3 leads to mixtures of dimers (3, 4) and trimers (5, 6) in yields ranging from 40 to 60percent.Increasing cation size in the added carbonate raises the amount of trimers 5, 6 relative to the dimers 3, 4.In the pyridine series sodium carbonate leads to predominant formation of the trimer 6, indicating a template effect.In the pyridine and the xylylene series the cesium effect leads to an approx. 40 : 60 ratio of dimer and trimer, which shows that a template effect seems not to be effective in this cesium assisted cyclization.
