1257442-51-5Relevant academic research and scientific papers
Dimethyl acetylenedicarboxylate and phospholes: A variety of reaction pathways
Huang, Congbao,Liu, Hui,Zhang, Jianzhen,Duan, Zheng,Mathey, Francois
, p. 5498 - 5502 (2010)
Correcting an earlier report, the reaction of 1-phenyl-3,4- dimethylphosphole (1a) with an excess amount of dimethyl acetylenedicarboxylate (DMAD) at room temperature affords the stable cyclopentadienylidenephosphorane 3a resulting from unexpected deoxygenation of initially formed [phosphole + 2DMAD] adduct 2a by the starting phosphole, The identity of 3a was established by X-ray crystal structure analysis. DFT calculations on a model [1+2] adduct similar to 2a shows a bent allenic structure and an ambident reactivity for the terminal carbon of the (DMAD)2 chain. Cyclopentadienylidenephosphorane 3b is also obtained with 1-benzyl phosphole lb. With 1-stannylphosphole 1c, a 1:3 adduct with a seven-membered ring (i.e., 5) is obtained. It was also characterized by X-ray crystal structure analysis, Finally, with 1-benzyl-2-benzoylphosphole 1d, the P lone pair has lost its nucleophilicity and a [4+2] cycloaddition takes place with the dienol tautomer of the unsaturated ketone to give phosphindole 6, also characterized by X-ray.
