نتایج جستجو برای: phosphorus ylide
تعداد نتایج: 41924 فیلتر نتایج به سال:
The cycloaddition of azomethine ylides to [60]fullerene (C60) has been studied in ortho-dichlorobenzene (o-DCB) by evaluating the impact an ionic liquid (IL) additive. solvent effect addressed activation parameters and boosting microwave (MW) induced dielectric heating. IL additive plays a twofold role stabilizing dipolar ylide intermediate favoring retro-cycloaddition at high temperature regim...
The first total synthesis of the dihydrooxepine-containing epidithiodiketopiperazine (ETP) (-)-acetylaranotin (1) is reported. The key steps of the synthesis include an enantioselective azomethine ylide (1,3)-dipolar cycloaddition reaction to set the absolute and relative stereochemistry, a rhodium-catalyzed cycloisomerization/chloride elimination sequence to generate the dihydrooxepine moiety,...
The reactions of isolable dialkylsilylene 10 with various aldimines proceed smoothly at low temperatures to give diverse products depending on the substituents on the imine. The reactions of 10 with 4-XC(6)H(4)CH=NPh [X = H (11a), MeO (11b), and Cl (11c)] give the corresponding silaaziridines 12a-12c in high yields, which are thermally very stable and remain intact in the air and moisture for a...
We report a new catalyst system that should enhance the use of enantioselective 1,3-dipolar cycloadditions of azomethine ylides with electronic-deficient olefins in the divergent pathways of diversity-oriented synthesis (DOS). The underlying reaction is of considerable interest in DOS because its stereospecificity enables stereochemical diversification of up to four tetrahedral centers on pyrro...
The ylide-functionalized diisopropyl phosphine (prYPhos) promotes Pd-catalyzed Suzuki-Miyaura couplings of aryl chlorides and bromides with arylboronic acids. Using Pd2(dba)3/prYPhos as the catalyst K2CO3 base, various (hetero)biaryls were synthesized in 45–98% yields at mild reaction conditions, tolerating sensitive functional groups steric hindrance. electron rich, sterically demanding ligand...
Ruminant phosphorus excretion and metabolism were studied through a database. Faecal endogenous phosphorus is the main pathway of phosphorus excretion and averages 0.85 of total faecal phosphorus. The remaining 0.15 is unabsorbed dietary phosphorus. Faecal endogenous phosphorus is mainly unabsorbed phosphorus, with saliva being the major source, and is correlated to factors influencing saliva s...
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