23094-22-6Relevant academic research and scientific papers
Palladium-Catalyzed α,β-Dehydrogenation of Esters and Nitriles
Chen, Yifeng,Romaire, Justin P.,Newhouse, Timothy R.
, p. 5875 - 5878 (2015/05/27)
A highly practical and general palladium-catalyzed methodology for the α,β-dehydrogenation of esters and nitriles is reported. Generation of a zinc enolate or (cyanoalkyl)zinc species followed by the addition of an allyl oxidant and a palladium catalyst results in synthetically useful yields of α,β-unsaturated esters, lactones, and nitriles. Preliminary mechanistic investigations are consistent with reversible β-hydride elimination and turnover-limiting, propene-forming reductive elimination.
Diagnostic fragmentations of adducts formed between carbanions and carbon disulfide in the gas phase. A joint experimental and theoretical study
MacLean, Micheal J.,Walker, Scott,Wang, Tianfang,Eichinger, Peter C. H.,Sherman, Patrick J.,Bowie, John H.
experimental part, p. 371 - 377 (2010/02/16)
Selected carbanions react with carbon disulfide in a modified LCQ ion trap mass spectrometer to form adducts, which when collisionally activated, decompose by processes which in some cases identify the structures of the original carbanions. For example (i) C6H5- + CS 2→ C6H5CS2-→ C6H5S- + CS, occurs through a 3-membered ring ipso transition state, and (ii) the reaction between C6H 5CH2- and CS2 gives an adduct which loses H2S, whereas the adduct(s) formed between o-CH 3C6H5- and CS2 loses H2S and CS. Finally, it is shown that decarboxylation of C 6H5CH2CH2CO2- produces the β-phenylethyl anion (PhCH2CH2 -), and that this thermalized anion reacts with CS2 to form C6H5CH2CH2CS2 - which when energized fragments specifically by the process C 6H5CH2CH2CS2 -→ C6H5CH2-CHC(S)SH → [(C6H5CH2CHCS) -SH] → C6H5CH2CCS- + H2S. Experimental findings of processes (ii) and (iii) were aided by deuterium labelling studies, and all reaction profiles were studied by theoretical calculations at the UCCSD(T)/6-31+G(d,p)//B3LYP/6-31+G(d,p) level of theory unless indicated to the contrary.
Raney Co-Al Alloy, an Efficient Catalyst for the Selective Incorporation of Deuterium Atoms at the Benzylic Position of Aromatic Compounds
Tsukinoki, Takehito,Ishimoto, Keiko,Mukumoto, Mamoru,Suzuki, Michio,Kawaji, Takatoshi,Nagano, Yoshiaki,Tsuzuki, Hirohisa,Mataka, Shuntaro,Tashiro, Masashi
, p. 66 - 67 (2007/10/03)
By using Raney Co-Al in 20% Na2CO3-D2O solution, deuterium atoms can be selectively incorporated into the benzylic position of aromatic compounds in high deuterium content.
On the Generation and Characterization of the Spirooctadienyl Anion in the Gas Phase
Maas, Wilfrid P. M.,Veelen, Peter A. van,Nibbering, Nico M. M.
, p. 546 - 558 (2007/10/02)
Three routes have been explored in both a high-pressure chemical ionization (CI) source and a low-pressure Fourier transform ion cyclotron resonance (FT-ICR) cell to generate the spirooctadienyl anion in the gas phase: (i) proton abstraction from spiroocta-4,6-diene; (ii) expulsion of trimethylsilyl fluoride by phenyl ring participation following fluoride anion attack upon the silicon centre of 2-phenylethyl trimethylsilane; and (iii) collisionally induced dissociation (CID) of the carboxylate anion of 3-phenylpropanoic acid via carbon dioxide loss.From comparison of the CID spectra of various reference (1-) ions with those of the (1-) ions with those of the (1-) ions which could be generated via the routes (i) and (iii) in the CI source it can be concluded that only the third route yields a (1-) in whose CID spectrum is not inconsistent with the one expected for the spirooctadienyl anion.In the FT-ICR cell (1-) ions are generated along all three routes; their structures have been identified by specific ion-molecule reactions and appear to be different.Route (i) yields an α-methyl benzyl anion, probably due to isomerization within the ion-molecule complex formed.An ortho-ethylphenyl anions is formed along route (ii), presumably due to an intramolecular ortho proton abstraction in the generated trimethylsilyl fluoride solvated 2-phenylethyl primary carbanion.The (1-) ion formed along route (iii) shows reactions similar to those of the 1,1-dimethylcyclohexadienyl anion which is structurally related to the spirooctadienyl anion.Furthermore, the (1-) ion generated via route (iii) reacts with hexafluorobenzene under expulsion of only one hydrogen fluoride molecule which contains exclusively one of the original phenyl ring hydrogen atoms.On the basis of all these observations it is therefore quite likely that the spirooctadienyl anion is formed by collisionally induced decarboxylation of the 3-phenylpropanoic acid carboxylate anion and can be a long-lived and stable species in the gas phase.
