119450-03-2Relevant academic research and scientific papers
Carbene-catalyzed LUMO activation of alkyne esters for access to functional pyridines
Mou, Chengli,Wu, Jichang,Huang, Zhijian,Sun, Jun,Jin, Zhichao,Chi, Yonggui Robin
supporting information, p. 13359 - 13362 (2017/12/26)
A carbene-catalyzed LUMO activation of α,β-unsaturated alkyne esters is reported. This catalytic process allows for effective reactions of alkyne esters with enamides to synthesize functional pyridines via simple protocols. A previously unexplored unsaturated alkyne acyl azolium intermediate is involved in the key step of the reaction.
A versatile synthesis of 1-benzoheteroepines containing group 14, 15, and 16 heavier elements via a common 1,6-dilithium intermediate
Yasuike, Shuji,Shiratori, Shin-Ichi,Kurita, Jyoji,Tsuchiya, Takashi
, p. 1108 - 1114 (2007/10/03)
Fully unsaturated group 14 (Si, Ge, and Sn), group 15 (P, As, Sb, and Bi) and group 16 (S, Se, and Te) 2-trimethylsilyl-1-benzoheteroepines (16a- j), including the first isolated examples of bismepines, have been prepared by reaction of the corresponding electrophilic metal reagents (MX2 or MX4; M=group 14, 15, and 16 heavier elements) with the key 1,6-dilithium intermediate (9), generated from the common starting compound (Z,Z)-1-bromo- 4-(2-bromophenyl)-1-trimethylsilyl-1,3-butadiene (14) by treatment with tert- butyllithium. The trimethylsilyl group in 16b-j was readily removed by treatment with tetrabutylammonium fluoride to give the desired C- unsubstituted 1-benzoheteroepines (1b-j). Single crystal X-ray analyses of 1d (P) and 1f (Sb) revealed that the seven-membered rings exist in boat conformations with the heteroatoms at the bows. All obtained C-unsubstituted group 15 and 16 1-benzoheteroepines (1d-j) were thermolabile in solution towards heteroatom extrusion, while heteroepines (16d-j) having the bulky trimethylsilyl group at the 2-position were much more stable than 1d-j. The half-lives of 1d-j estimated from 1H-NMR spectral analysis indicate that the thermal stabilities of 1d-j decrease in the order 1f (Sb)>1d (P)>1e (As)>1g (Bi) in the group 15 heteroepines and 1j (Te)>1i (Se)>1h (S) in the group 16 heteroepines.
