71521-85-2Relevant academic research and scientific papers
Water and Sodium Chloride: Essential Ingredients for Robust and Fast Pd-Catalysed Cross-Coupling Reactions between Organolithium Reagents and (Hetero)aryl Halides
Dilauro, Giuseppe,Quivelli, Andrea Francesca,Vitale, Paola,Capriati, Vito,Perna, Filippo Maria
supporting information, p. 1799 - 1802 (2019/01/25)
Direct palladium-catalysed cross-couplings between organolithium reagents and (hetero)aryl halides (Br, Cl) proceed fast, cleanly and selectively at room temperature in air, with water as the only reaction medium and in the presence of NaCl as a cheap additive. Under optimised reaction conditions, a water-accelerated catalysis is responsible for furnishing C(sp3)–C(sp2), C(sp2)–C(sp2), and C(sp)–C(sp2) cross-coupled products, in competition with protonolysis, within a reaction time of 20 s, in yields of up to 99 %, and in the absence of undesired dehalogenated/homocoupling side products even when challenging secondary organolithiums serve as the starting material. It is worth noting that the proposed protocol is scalable and the catalyst and water can easily and successfully be recycled up to 10 times, with an E-factor as low as 7.35.
DETERMINATION OF DOUBLE BOND POSITION AND GEOMETRY OF OLEFINS BY MASS SPECTROMETRY OF THEIR DIELS-ALDER ADDUCTS.
Kidwell,Biemann
, p. 2462 - 2465 (2007/10/02)
The Diels-Alder reaction of olefins with ketals of tetrachlorocyclopentadiene produces adducts, the mass spectra of which clearly identify the position and geometry of the original double bond. The loss of either substituent determines the position of the olefin, and the relative abundances of the resultant ions can be related to the geometry. These ions are at least 5-fold more abundant on the product derived from the Z-olefin. The spectra are simpler than the spectra of other derivatives previously used for this purpose and the sensitivity of the technique is such that it can be applied at the microgram level. The ions indicative of the molecular weight of the adduct are very prominent even though the molecular ion is absent.
