420121-32-0Relevant academic research and scientific papers
Palladium-catalyzed direct coupling reaction of propargylic alcohols with arylboronic acids
Yoshida, Masahiro,Gotou, Takahiro,Ihara, Masataka
, p. 5573 - 5575 (2004)
The direct coupling of propargylic alcohols with arylboronic acids has been achieved using palladium catalyst. Various propargylic alcohols and arylboronic acids can be coupled to afford the corresponding allenic and propargylic arenes, which are selectiv
Tuning of regioselectivity in the coupling reaction involving allenic/propargylic palladium species
Ma, Shengming,Zhang, Aibin
, p. 2287 - 2294 (2007/10/03)
Two different types of coupling patterns for the Pd(O)-catalyzed coupling reaction of allenic/propargylic zinc reagents with organic halides or propargylic carbonates (acetate) with the corresponding organometallic reagents were observed. After studying the controlling factors on the regioselectivity of this reaction, we demonstrated that the steric hindrance of both reactants and the types of organic halides determine the regioselectivity of this coupling reaction. By subtle choosing of the substrates, the regioselectivity can be tuned. On the basis of these results, new methodologies for the highly regio- and stereoselective synthesis of 6-substituted hex-5-yn-2-enoates and 4,6-dialkylhexa-2,4,5-trienoates have been developed. Some of the products synthesized by the carbonate protocol cannot be prepared by the lithiation protocol because the regioselectivity of lithiation of dialkyl-substituted internal alkynes is an intrinsic problem.
A NOVEL ORTHO-SUBSTITUENT EFFECT ON FORMATION OF VINYL CATIONS IN THE PHOTOLYSIS OF VINYL BROMIDES
Kitamura, Tsugio,Muta, Tomonobu,Kobayashi, Shinjiro,Taniguchi, Hiroshi
, p. 643 - 644 (2007/10/02)
Introduction of a substituent into ortho-position of β-aryl group in a vinyl bromide resulted in the preferential formation of a vinyl cation in the photolysis.It is considered that the steric repulsion of β-aryl groups makes a convenient conformation for an electron transfer from the aromatic ring to the halogen atom in the radical pair.
