121775-89-1Relevant academic research and scientific papers
Bismuth-Mediated Diastereoselective Allylation Reaction of Carbonyl Compounds with Cyclic Allylic Halides or Cinnamyl Halide
Liu, Xuan-Yu,Cheng, Bu-Qing,Guo, Yi-Cong,Chu, Xue-Qiang,Li, Yong-Xin,Loh, Teck-Peng,Shen, Zhi-Liang
, p. 542 - 549 (2019)
An efficient diastereoselective allylation of various carbonyl compounds with cyclic allylic halides by using commercially available bismuth powder in the presence of LiI was developed. Among all the metals screened, bismuth was found to be the best mediator for the transformation. The reactions involving various cyclic allylic halides proceeded smoothly at room temperature to produce the desired homoallylic alcohols in good to excellent yields with high diastereoselectivities (>99:1 dr). Reversed diastereoselectivity was obtained when carbonyl substrate (e. g., 2-pyridinecarboxaldehyde, glyoxylic acid) containing chelating substituent was used in the allylation reaction. In addition, the reactions involving acyclic (E)-cinnamyl bromide as substrate worked equally well with high diastereocontrol. (Figure presented.).
An efficient approach to (E)-β-methyl Baylis-Hillman adducts via indium-mediated allylation of aldehydes in aqueous media
Cha, Joo Hwan,Pae, Ae Nim,Choi, Kyung Il Il,Cho, Yong Seo,Koh, Hun Yeong,Lee, Eun
, p. 2079 - 2081 (2007/10/03)
A new method has been developed for the synthesis of (E)-β-methyl Baylis-Hillman adducts with high E-Z (>93%) selectivity in modest to good yields. The process consists of two steps: an indium-mediated allylation reaction and a simple base-catalyzed isomerization step. Various aldehydes were allylated with allyl bromides using indium under very mild conditions in aqueous media. The allylation reactions of aromatic and aliphatic aldehydes were largely accelerated by the presence of HCl.
Dienediolates from Unsaturated Carboxylic Acids. Reaction with para-Substituted Benzaldehydes. Electronic Effects on Regioselectivity
Parra, Margarita,Mestres, Ramon,Aparicio, Domitila,Durana, Nieves,Rubiales, Gloria
, p. 327 - 332 (2007/10/02)
Regioselectivity α/γ ratios for addition of the lithium dienediolate of crotonic acid to para-substituted benzaldehydes are subject to small electronic effects when reactions are carried out at low temperature, but strong influence by substituents is observed on heating for 1 h at 60 deg C.A linear correlation is then found between regiochemical ratios and ?p parameters.Stereoselectivity RR/RS ratios (33:66 to 43:57) for α-adducts obtained in the cold do not depend on the substituents.
