18421-23-3Relevant academic research and scientific papers
Triphosgene and DMAP as Mild Reagents for Chemoselective Dehydration of Tertiary Alcohols
Ganiu, Moshood O.,Cleveland, Alexander H.,Paul, Jarrod L.,Kartika, Rendy
supporting information, p. 5611 - 5615 (2019/08/01)
The utility of triphosgene and DMAP as mild reagents for chemoselective dehydration of tertiary alcohols is reported. Performed in dichloromethane at room temperature, this reaction is readily tolerated by a broad scope of substrates, yielding alkenes preferentially with the (E)-geometry. While formation of the Hofmann products is generally favored, a dramatic change in alkene selectivity toward the Zaitzev products is observed when the reaction is carried out in dichloroethane at reflux.
Synthesis of polysubstituted olefins by Pd-catalyzed cross-coupling reaction of tosylhydrazones and aryl nonaflates
Barluenga, Jose,Florentino, Lucia,Aznar, Fernando,Valdes, Carlos
, p. 510 - 513 (2011/03/22)
Aryl nonaflates are employed as electrophiles in the Pd-catalyzed cross-coupling with tosylhydrazones affording di-, tri-, and tetrasubstituted olefins. Fine tunning of the reaction conditions are required to accomplish the coupling successfully, includin
Steric Effects in Photochemical Cycloadditions of 9-Phenanthrenecarboxylates
Itoh, Hiroki,Shibata, Hirofumi,Wagatsuma, Marie,Nanjoh, Mari,Senda, Yasuhisa,et al.
, p. 340 - 343 (2007/10/02)
Efficiency of photochemical intramolecular and intermolecular cycloadditoin of 9-phenanthrenecarboxylate-anethole systems is dependent on the structure of anethole moiety.Reduction in reactivity of the anethole moiety by steric effects is explained in terms of decrease in coefficients of frontier orbitals on the double bond due to twisting of the anisyl moiety.
Structural Effects on Twisted Olefin Triplet Lifetimes. Styrene Derivatives
Caldwell, R. A.,Cao, C. V.
, p. 6174 - 6180 (2007/10/02)
The triplet lifetimes in methanol of a series of anisylalkenes and anisylcycloalkenes, including several phenyl analogues, have been determined by nanosecond flash kinetic absorption spectrophotometry with nitrogen laser excitation.Electron-transfer scavenging by paraquat dication, PQ2+, (methyl viologen) afforded the readily detectable reduced species PQ+*.Both triplet lifetimes and rate constants for electron transfer from triplet to PQ2+ were determined.The results indicate that acyclic styrene triplets prefer the twisted, "1,2-biradical" structure.Lifetimes are increased by vinyl deuteration, by increasing alkylation, and by constraint within a small ring; in the absence of geometric constraints, the dominant influence on the triplet lifetimes is the extent of substitution at the double bond.Mechanisms for intersystem crossing are discussed, and the tentative conclusion is reached that nuclear motions are important.
