نتایج جستجو برای: spiro heterobicyclic rings
تعداد نتایج: 50633 فیلتر نتایج به سال:
in the present of methylimidazolium hydrogen sulfate, the synthesis of arylidene heterobicyclic pyrimidinones is studied by condensation of aromatic aldehyde, cyclopentanone, and urea or thiourea. using solvent-free conditions, non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.
this paper is an attempt to generalize, simultaneously, the ring of real-valued continuous functions and the ring of real-valued measurable functions.
Four new nor-spiro-azaphilones, thielavialides A-D (1- 4), a new bis-spiro-azaphilone, thielavialide E (5), together with pestafolide A (6), were isolated from the endophytic fungal strain, Thielavia sp. PA0001, occurring in the healthy leaf tissue of aeroponically grown Physalis alkekengi. The structures and relative configurations of 1-5 were established on the basis of their MS and NMR data....
We have developed a simple methodology to transform cis-syn-cis-triquinane derivative 2 into the diindole based macrocycle 6 involving Fischer indolization and ring-closing metathesis (RCM). Various spiro-polyquinane derivatives have been assembled via RCM as a key step.
let $r$ be an associative ring with identity and $z^*(r)$ be its set of non-zero zero divisors. the zero-divisor graph of $r$, denoted by $gamma(r)$, is the graph whose vertices are the non-zero zero-divisors of $r$, and two distinct vertices $r$ and $s$ are adjacent if and only if $rs=0$ or $sr=0$. in this paper, we bring some results about undirected zero-divisor graph of a monoid ring ov...
Among the new generation photovoltaics, perovskite solar cell (PSC) technology reached top efficiencies in a few years. Currently, main objective to further develop PSCs is related fabrication of stable devices with cost-effective materials and reliable processes achieve possible industrialization pathway. In n-i-p device configuration, hole transporting material (HTM) used most highly doped or...
Four high triplet organic semi-conductors based on the donor-spiro-acceptor design (D-spiro-A) have been synthesized. Their physicochemical and photophysical properties have been studied, compared and discussed in light of the nature of their respective donor/acceptor units. The four compounds have been used as host materials in efficient sky-blue (EQE 4 10% at 10 mA cm ) phosphorescent organic...
In the title spiro-indeno-quinoxaline compound, C(22)H(14)N(6)O·C(2)H(6)O, the five-membered ring of the indene unit and the pyran ring are perpendicular [89.11 (3)°]. In the crystal, N-H⋯N hydrogen bonds connect the spiro-indeno-quinoxaline mol-ecules, and the ethanol solvent mol-ecules complete the hydrogen-bond network via O-H⋯N and N-H⋯O inter-actions.
A series of functionalized spiro[indoline-3,2'-oxiran]-2-ones was efficiently synthesized by Darzens reaction of phenacyl bromides with isatins both with N-alkyl groups and without N-substituent in the presence of potassium carbonate as a base catalyst. When two equivalents phenacyl bromides were used in the reaction, the N-substitution reaction of isatin also finished with the formation of spi...
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