Generation and Reactions of Trifluoromethylethenyl Titanium(II) Species
摘要:
The reaction of (trifluoromethyl)dimethylphenylsilyacetylene and (eta(2)-propene)Ti((OPr)-Pr-i)(2) generated in situ smoothly proceeded giving the corresponding (eta(2)-1-dimethylphenyl-silyl-2-trifluoromethylalkyne)Ti((OPr)-Pr-i)(2), which reacted with aldehydes and ketones to afford the corresponding addition products in good yields with good to excellent regioselectivity.
enantiomeric excess (71%–83% ee). Ru-BINAP-catalyzed hydrogenation converted 2-trifluoromethyl-acrylic acid to the corresponding saturated acid, the ester-ification and reduction of which gave opticallyactive2-(trifluoromethyl)propan-1-ol in 80% ee.
Rapid and Slow Generation of 1-Trifluoromethylvinyllithium: Syntheses and Applications of CF3-Containing Allylic Alcohols, Allylic Amines, and Vinyl Ketones
1‐(Trifluoromethyl)vinylation is accomplished in two protocols by the in situ generation of thermally unstable 3,3,3‐trifluoroprop‐1‐en‐2‐yllithium (1): 1) a rapid lithium–halogen‐exchange reaction of 2‐bromo‐3,3,3‐trifluoroprop‐1‐ene (2) takes effect with sec‐BuLi at −105 °C to generate vinyllithium 1, which reacts with more reactive electrophiles, such as aldehydes and N‐tosylimines before its decomposition
This work describes the optimization process for the synthesis of β-trifluoromethylated ketonesfrom trifluoromethylated allylicalcohols. This transformation proceeds through a ruthenium catalyzed isomerization under mild conditions with high atom economy. The effect of the CF3 group was analyzed and it provides fundamental insights into the isomerization reaction.
A Facile Synthesis of<i>N</i>-[2-(Trifluoromethyl)allyl]amides and Their Transformation into Angularly Trifluoromethylated Bicyclic Cyclopentenones
作者:Ryo Nadano、Junji Ichikawa
DOI:10.1246/cl.2007.22
日期:2007.1
On treatment with sec-BuLi at −105 °C, 2-bromo-3,3,3-trifluoropropene undergoes rapid lithium–halogen exchange to generate thermally unstable 1-(trifluoromethyl)vinyllithium, which reacts with N-tosylimines to afford N-[2-(trifluoromethyl)allyl]amides in high yield. Propargylation of the amides, followed by the Pauson–Khand reaction, readily provides pyrrolidine ring-fused cyclopentenones with an angular trifluoromethyl group.
1-(Trifluoromethyl)vinylation via Oxirane or Oxetane Ring-Opening: A Facile Synthesis of 4- or 5-Hydroxy-Functionalized 2-Trifluoromethyl-1-alkenes
作者:Junji Ichikawa、Ryo Nadano
DOI:10.1055/s-2005-918413
日期:——
Introduction of a 1-(trifluoromethyl)vinyl group has been accomplished by the reaction of thermally unstable 1-(trifluoromethyl)vinyllithium (1) with strained cyclic ethers. Treatment of 2-bromo-3.3.3-trifluoropropene with butyllithium generates 1. which in turn reacts with several oxiranes or an oxetane at -100 °C in the presence of BF 3 .OEt 2 to afford the corresponding 2-trifluoromethyl- -1-alkenes