50868-73-0Relevant articles and documents
Pendant Alkoxy Groups on N-Aryl Substitutions Drive the Efficiency of Imidazolylidene Catalysts for Homoenolate Annulation from Enal and Aldehyde
Kyan, Ryuji,Mase, Nobuyuki,Narumi, Tetsuo,Sato, Kohei
supporting information, p. 19031 - 19036 (2020/08/25)
Hydrogen-transfer in the tetrahedral intermediate generated from an imidazolylidene catalyst and α,β-unsaturated aldehyde forms a conjugated Breslow intermediate. This is a critical step affecting the efficiency of the NHC-catalyzed γ-butyrolactone formation via homoenolate addition to aryl aldehydes. A novel type of imidazolylidene catalyst with pendant alkoxy groups on the ortho-N-aryl groups is described. Catalyst of this sort facilitates the formation of the conjugated Breslow intermediate. Studies of the rate constants for homoenolate annulation affording γ-butyrolactones, reveal that introduction of the oxygen atoms in the appropriate position of the N-aryl substituents can increase the efficiency of imidazolylidene catalysts. Structural and mechanistic studies revealed that pendant alkoxy groups can be located close to the proton of the tetrahedral intermediate, thereby facilitating the proton transfer.
Expeditious synthesis of benzopyrans via lewis acid-catalyzed C-H functionalization: Remarkable enhancement of reactivity by an ortho substituent
Mori, Keiji,Kawasaki, Taro,Sueoka, Shosaku,Akiyama, Takahiko
supporting information; experimental part, p. 1732 - 1735 (2010/09/05)
An expeditious construction of a benzopyran skeleton via Lewis acid-catalyzed C-H functionalization was achieved. In this process, a [1,5] hydride shift and 6-endo cyclization successively occurred to give benzopyrans. The presence of substituents ortho to the alkoxy group significantly enhanced the reactivity, affording the desired compounds in excellent chemical yields with short reaction times.
New staves for old barrels: Regioisomeric (12,2 2,33,42,53,62,7 3,82)-p-octiphenyl rods with an NMR tag
Ronan, Dawn,Jeannerat, Damien,Pinto, Andre,Sakai, Naomi,Matile, Stefan
, p. 168 - 176 (2007/10/03)
The usefulness of rigid-rod p-octiphenyls with the novel 1 2,22,33,42,53,6 2,73,82-motif as staves in rigid-rod β-barrel pores is evaluated. Comparison with the known
