Auto Tandem Catalysis: Asymmetric Vinylogous Cycloaddition/Kinetic Resolution Sequence for the Enantioselective Synthesis of Spiro‐Dihydropyranone from Benzylidene Meldrum's Acid
has been achieved from ketone-derived benzylidene Meldrum's acid and α-ketolactones to provide spirolactone dihydropyranones with more than 99% ee. An Auto Tandem Catalysis (ATC) process resulting from dual and complementary role of (DHQ)2PHAL organocatalyst resulted in a sequence involving an asymmetric vinylogous formal (4+2) cycloaddition of benzylidene and the subsequent kinetic resolution operating
Employing Pd(OAc)2 immobilized on amorphous N,N-diethylaminopropyl alumina, Suzuki-Miyaura coupling of aryl halide with arylboronic acid was realized in 50% aqueous ethanol at room temperature, which enabled repeated use up to four times in 96% average yield and achieved a turnover number of 15 000.
Air- and moisture-stable Xantphos-ligated palladium dialkyl complex as a precatalyst for cross-coupling reactions
作者:Rina Takahashi、Koji Kubota、Hajime Ito
DOI:10.1039/c9cc06946a
日期:——
xantphos has been employed in a variety of palladium-catalyzed cross-couplingreactions, there has been little progress in developing Xantphos-ligated precatalysts. In this report, we describe a Xantphos-ligated palladium dialkyl complex that acts as a powerful precatalyst for C-N, C-S, and C-C cross-couplingreactions. This precatalyst is air- and moisture stable but can be thermally activated in the
Fluorosolvatochromism of four furanyl- or thiophenyl-substituted acetophenone derivatives is suitable to measure environmental effects.
四种取代苯乙酮衍生物的氟烷基或硫代苯基溶剂效应色谱法适用于测量环境影响。
Organogold(I) Phosphanes in Palladium-Catalyzed Cross-Coupling Reactions in Aqueous Media
作者:Miguel Peña-López、Luis A. Sarandeses、José Pérez Sestelo
DOI:10.1002/ejoc.201201720
日期:2013.5
Cross-coupling reaction of organogold(I) phosphanes with organic electrophiles in aqueousmedia has been investigated. Reactions between isolated aryl-, alkenyl-, or alkynylgold(I) phosphanes and aryl halides or triflates, alkenyl halides, and allyl acetates proceed under palladium catalysis conditions at room temperature or 80 °C in water with THF as a co-solvent. The couplingreactions give good yields