1227407-95-5Relevant articles and documents
Push-pull alkenes from cyclic ketene-N,N′-acetals: a wide span of double bond lengths and twist angles
Ye, Guozhong,Chatterjee, Sabornie,Li, Min,Zhou, Aihua,Song, Yingquan,Barker, Bobby Lloyd,Chen, Chunlong,Beard, Debbie J.,Henry, William P.,Pittman, Charles U.
experimental part, p. 2919 - 2927 (2010/06/16)
Push-pull alkenes can be quickly accessed by cyclic ketene-N,N′-acetal chemistry. A number of push-pull structures with a wide span of double bond lengths and twist angles were synthesized from the reactions of (1) N,N′-dimethyl cyclic ketene-N,N′-acetals with isocyanates, (2) the products from (1) with isocyanates, (3) 2-methylimidazoline and 2-methyl-1,4,5,6-tetrahydropyrimidine with diacid chlorides, (4) 2-methylimidazoline, and 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine with benzoyl chlorides, and (5) 1,2-dimethylimidazoline and 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine with aryl isocyanates. These reactions proceed under very mild conditions and give moderate to excellent yields. X-ray crystallographic analysis of eight pxush-pull alkenes indicates that the central double bond lengths and twists are sensitive to the ring sizes (5 or 6), ring structures (fused or non-fused), electron donating and withdrawing strengths of pushing and pulling portions, respectively, number of electron pushing or pulling groups and substituent steric effects.
