23394-15-2Relevant academic research and scientific papers
Direct synthesis of adipic acid esters via palladium-catalyzed carbonylation of 1,3-dienes
Yang, Ji,Liu, Jiawang,Neumann, Helfried,Franke, Robert,Jackstell, Ralf,Beller, Matthias
, p. 1514 - 1517 (2020/01/08)
The direct carbonylation of 1,3-butadiene offers the potential for a more cost-efficient and environmentally benign route to industrially important adipic acid derivatives. However, owing to the complex reaction network of regioisomeric carbonylation and isomerization pathways, a selective practical catalyst for this process has thus far proven elusive. Here, we report the design of a pyridyl-substituted bidentate phosphine ligand (HeMaRaphos) that, upon coordination to palladium, catalyzes adipate diester formation from 1,3-butadiene, carbon monoxide, and butanol with 97% selectivity and 100% atom-economy under industrially viable and scalable conditions (turnover number > 60,000). This catalyst system also affords access to a variety of other di- and triesters from 1,2- and 1,3-dienes.
Thermal and optical properties of chiral twin liquid crystalline bis(cholesteryl) alkanedioates
Marcelis, Antonius T. M.,Koudijs, Arie,Sudhoelter, Ernst J. R.
, p. 1469 - 1472 (2007/10/03)
The thermal and optical properties of a series of bis(cholesteryl) alkanedioates were investigated. The melting points, the cholesteric to isotropic transition temperatures, the entropy changes at this temperature and the selective reflection wavelengths of the cholesteric phase all exhibit an odd-even effect as a function of spacer length. This is attributed to a difference in the ordering of the cholesteric phase as a function of the parity of the spacer. Because the properties of the members of the series with a short spacer could not be measured for several reasons, their properties were also determined as a 5 wt% solution in a cholesteric host. A similar odd-even influence on the cholesteric to isotropic transition temperatures and the optical properties of the host was observed as for the pure compounds. The influence on the properties of the host is stronger for compounds with a short spacer than for compounds with a longer spacer.
