Furans furnished

Furnished to Dtic Contained

Furnished to Dtic Contained

The possibilities for tunable electrically small antennas are explored and analyzed. Although experimental determinations were made of impedance characteristics from 30 to 220 MHz, the objective was to study the possibility of tuning and bandwidth control for antennas in the range 30 to 100 MHz. A considerable part of the discussion is devoted to acceptable circidt representations or models for...

Asymmetric hydrogenation of disubstituted furans.

An enantioselective hydrogenation of disubstituted furans has been developed by using a chiral ruthenium catalyst with N-heterocyclic carbene ligands. This reaction converts furans into valuable enantioenriched disubstituted tetrahydrofurans.

Asymmetric homogeneous hydrogenation of 2,5-disubstituted furans.

A homogeneous catalyst system for the asymmetric cis-hydrogenation of 2,5-disubstituted furans leading to 2',3'-dideoxynucleoside analogues is described. Best enantioselectivities (ee values of up to 72%) were obtained with cationic rhodium complexes ligated by diphospholanes of the butiphane family. The selectivity of the hydrogenation was reversed by the addition of a base or a polar protic s...

Production of Sustainable Aromatics from Biorenewable Furans

ed by the ether oxygen of oxanorbornene and dehydration can occur along the pathway illustrated in Figure 7.10. Figure 7.10 Proton transfer from adsorbed DMF to the cycloadduct. At the same time, proton transfer of the acidic H of the adsorbed DMF complex to p-xylene is neither energetically favorable (∆G = +27.6 kcal/mol) and has a significant energy barrier (Ea = +26.6 kcal/mol). Once the pro...