From Phenols to Azulenes: An Extended and Versatile Route to Polyalkylated Azulenes with Variable Substitution Patterns at the Seven- and Five-membered Ring
Lastereochimie de l'addition depends des facteurs steriques, du solvant, et de la nature des groupes activants。Ainsi les cetones acetyleniques donnent Exclusive les isomeres E (controle thermodynamique) et lesnitiles acetyleniques Fournissent seulement les isomeres Z (controle cinetique)
Asymmetricaddition of arylboroxines to beta-alkoxyacrylate esters proceeded in the presence of a rhodium complex coordinated with a chiral diene ligand to give high yields of beta-alkoxy-beta-arylcarboxylic acid esters with very high enantioselectivity.
Rhodium-Catalyzed Asymmetric Addition of Arylboronic Acids to β-Phthaliminoacrylate Esters toward the Synthesis of β-Amino Acids
作者:Takahiro Nishimura、Jun Wang、Makoto Nagaosa、Kazuhiro Okamoto、Ryo Shintani、Fuk-yee Kwong、Wing-yiu Yu、Albert S. C. Chan、Tamio Hayashi
DOI:10.1021/ja909642h
日期:2010.1.20
Rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids to beta-phthaliminoacrylate esters took place efficiently to give high yields of beta-aryl-beta-amino acid esters with 96-99% enantioselectivity, which was realized by use of a hydroxorhodium/chiral diene complex.
The stereochemistry of addition of trialkylammonium and pyridinium tetrafluoroborate salts to activated acetylenes. Preparation of novel dienophiles for Diels-Alder reactions
作者:Michael E. Jung、Keith R. Buszek
DOI:10.1021/ja00220a039
日期:1988.6
La stereochimiede l'addition depend des facteurs steriques, du solvant, etde la nature des groupes activants. Ainsi les cetones acetyleniques donnent exclusivement les isomeres E (controle thermodynamique) et les nitriles acetyleniques fournissent seulement les isomeres Z (controle cinetique)
Lastereochimie de l'addition depends des facteurs steriques, du solvant, et de la nature des groupes activants。Ainsi les cetones acetyleniques donnent Exclusive les isomeres E (controle thermodynamique) et lesnitiles acetyleniques Fournissent seulement les isomeres Z (controle cinetique)
From Phenols to Azulenes: An Extended and Versatile Route to Polyalkylated Azulenes with Variable Substitution Patterns at the Seven- and Five-membered Ring
作者:Matthias Nagel、Hans-Jürgen Hansen
DOI:10.1055/s-2002-25363
日期:——
Polyalkylated azulenes can easily be prepared from polyalkylphenyl propiolates which are transformed by dynamic gas phase thermo-isomerization (DGPTI) into polyalkylcyclohepta[b]furan-2(2H)-ones. The latter react thermally with enol ethers or enamines to the corresponding azulenes. The enamines may be generated in situ from corresponding aminals, especially, in cases where it is difficult to obtain the pure enamines due to their high reactivity.