Phenyl phenylseleno

Phenyl phenylseleno tellurium and diazomethane in diethyl ether produced bis[phenylseleno]methane, bis[phenyltelluro]methane, and phenylselenomethyl phenyl tellurium3. 

Phenyl Phenylseleno Tellurium 0.79 g (5 mmol) of benzeneselenol are dissolved in 5ml of anhydrous tetrahydrofuran. Under nitrogen, 2.6 ml of 2 molar ethyl magnesium bromide (5.2 mmol) in diethyl ether are added, the mixture is heated under reflux for 2 h, cooled to 0°, and a solution of phenyl tellurium bromide, prepared from 1.02 g (2.5 mmol) of diphenyl ditellurium and 0.40 g (2.5 mmol) of bromine in tetrahydro-furan/benzene, is added. The reaction mixture is then warmed to 20°. stirred at 20" for 30 min, then 40 ml of low-boiling petroleum ether followed by aqueous ammonium chloride solution are added. The organic layer is separated, washed with saturated aqueous sodium chloride, dried with anhydrous magnesium sulfate, filtered, and evaporated. The residue (1.38g) is plaeed on a eolumn containing 120g of silica gel G, the product (Rf 0.60) is eluted with petroleum ether, the eluate is evaporated, and reddish needles are obtained yield 1.13 g (63%) m.p, 48° (petroleum ether). 

Phenyl phenylselenomethyl tellurium and lithium diisopropylamide in tetrahydrofuran at —78" produced phenyl phenylseleno(lithio)methyl tellurium. This compound reacted with methyl iodide to give phenyl 1-phenylseleno-1-ethyl tellurium. Butyl lithium cleaved... 

Se-phenyl areneselenosulfonates (24) undergo facile free-radical addition to alkenes to produce / -phenylseleno sulfones (25) in excellent yield86,87 (see Scheme 7). The addition occurs regiospecifically and affords anti-Markovnikov products contrary to the analogous boron trifluoride catalyzed reaction which produces exclusively Markovnikov and highly stereospecific products86 (equation 37). Reaction 36 has been shown to have the radical... 

Free-radical addition of Se-phenyl areneselenosulfonates to acetylenes is also a facile process, occurring regiospecifically and stereoselectively to afford the E-isomer of a -(phenylseleno) vinyl sulfone (26) in high yield88. 

Cyclization of y-alkenyloximes (109) and (110) proceeds with strong electrophilic phenyl- selenating agents (293-295). This regioselective reaction provides the formation of (phenylseleno)methylsubstituted 1,2-oxazines (111) and... 

Die Umsetzung von 2-Brom-l-phenylseleno-cycloalkanen bzw. -alkanen, hergestellt durch Addition von Brom-phenyl-selenan an die C,C-Doppelbindung, mit Silbernitrit liefert ne-ben den 2-Nitro-l-phenylseleno-cycloalkanen bzw. -alkanen (24-32%) die 2-Hy-droxy-1-phenylseleno-Verbindungen (39-57%) in hoheren Ausbeuten z. B.2 ... 

AMIDES Bis(o-nitrophenyl)phenyl-phosphonate. N,N-Bis(2-oxo-3-oxazoli-dinyl)phosphordiainidic chloride. 2-Chloro-2-oxo-l,3,2-bcnzodioxa-ph05-phole. Iodine azide. N-Methyl-N-phenyl-benzohydrazonyl bromide. Phase-transfer catalysts. N-Phenylseleno-phthalimidc. (SEProlinol. 

Free-radical cyclization of phenyl selenide 15 to indolizidinone 16 represented a key step in the total synthesis of (—)-slaframine (equation 52). The two pairs of diastereomers were first separated and then hydrolyzed to the corresponding alcohols in 76% overall yield77. (TMS)3SiH-mediated acyl radical reactions from phenylseleno esters 17 have recently been utilized for the stereoselective synthesis of cyclic ethers78. In fact, the experimental conditions reported in equation 53 are particularly good for both improving cis diastereoselectivity and suppressing decarbonylation. 

Phenyl N-phenylphosphoramidochloridatc, 416 Phenylselenenylation, 219 Phenyl selenocyanate, 33, 416-417 (3-Phcnylselcnoindole, 37, 38 N-Phenylselenophthalimide, 417-418 3-Phenylseleno sulfones, 407, 408 (3-(Phenylseleno)vinyl sulfones, 408 Phenyl sulfates, 410 Phenylsulfinylacetonitrile, 418-419 4-(Phenylsulfmyl)butyric acids, 1... 

Allylphenyl selemdes.3 a-Phenylseleno ketones react with trimethylsilylmethyllithium to afford an adduct that on treatment with a catalytic amount of SnCl2 loses the elements of (CH3)3SiOH accompanied with a 1,3-migration of the phenylselenyl group to give a primary allyl phenyl selenide. 

---