An Enantioselective Approach toward 3,4-Dihydroisocoumarin through the Bromocyclization of Styrene-type Carboxylic Acids
摘要:
A facile and enantioselective approach toward 3,4-dihydroisocoumarin was developed. The method involved an amino-thiocarbamate catalyzed enantioselective bromocyclization of styrene-type carboxylic acids, yielding 3-bromo-3,4-dihydroisocoumarins with good yields and ee's. 3-Bromo-3,4-dihydroisocoumarins are versatile building blocks for various dihydroisocoumarin derivatives in which the Br group can readily be modified to achieve biologically important 4-O-type and 4-N-type 3,4-dihydroisocoumarin systems. In addition, studies indicated that, by refining some parameters, the synthetically useful 5-exo phthalide products could be achieved with good yields and ee's.
Selenium-Mediated Synthesis of Biaryls through Rearrangement
作者:Sohail A. Shahzad、Clotilde Vivant、Thomas Wirth
DOI:10.1021/ol100274e
日期:2010.3.19
A new cyclization of β-keto ester substituted stilbene derivatives using selenium electrophiles in the presence of Lewis acids is described. Substituted naphthols are obtained through cyclization and subsequent 1,2-rearrangement of arylgroups under very mild reaction conditions.
Verfahren zur Herstellung von (Z)-2-(2-Arylethenyl)-arylcarbonsäuren
申请人:BASF Aktiengesellschaft
公开号:EP0275501A1
公开(公告)日:1988-07-27
Herstellung von (Z)-2-(2-Arylethenyl)-arylcarbonsäuren der allgemeinen Formel I
in welcher A eine Gruppierung zur Vervollständigung eines aromatischen Ringsystems und Ar einen aromatischen Rest bedeutet, durch Umsetzung einer 2-Formyl-arylcarbonsäure der allgemeinen Formel II
mit einem (Arylmethyl)phosphoniumsalz der allgemeinen Formel III,
in der R¹, R² und R³ für organische Reste stehen und X Halogen bedeutet, in Gegenwart einer Base bei Temperaturen zwischen (-20) und +30°C, indem man die Umsetzung in Gegenwart eines C₁-C₅-Alkanols und/oder C₂-C₄-Alkandiols ausführt.
A facile and enantioselective approach toward 3,4-dihydroisocoumarin was developed. The method involved an amino-thiocarbamate catalyzed enantioselective bromocyclization of styrene-type carboxylic acids, yielding 3-bromo-3,4-dihydroisocoumarins with good yields and ee's. 3-Bromo-3,4-dihydroisocoumarins are versatile building blocks for various dihydroisocoumarin derivatives in which the Br group can readily be modified to achieve biologically important 4-O-type and 4-N-type 3,4-dihydroisocoumarin systems. In addition, studies indicated that, by refining some parameters, the synthetically useful 5-exo phthalide products could be achieved with good yields and ee's.