Ethene, bromo

Ethylene, bromo-(8) Ethene, bromo- (9) (593-50-2) Bicyclo[3.2.0]heptan-2-ol, 3,3-dimethyl- (9) (71221-67-5) Bis(copper(I) trif1uoromethanesulfonate)benzene complex Copper,... 

Ethene Bromo-irifluoro- ElOa, 279 (Educt) ElOb, 324/353/418/434/ 471F./506/508 (Educt) E10b2. 288/289/45.3 (Educl)... 

Ethene, bromo-Ethene, chloro-Ethene, 1,1-clichloro-... 

Poly(vinyl bromide) Bromoethylene polymer 2595 I -54-h Ethene, bromo-, homopolymer R (CzHjBr),... 

Photocycloaddition. Synthesis of the highly carcinogenic polycycHc hydrocarbons, eg (51) [72735-91-2] may be affected by photocycloaddition of 2-bromo-3-methoxy naphthoquinone [26037-61-6] with 1,1-diarylethylenes such as l,l-bis(p-methoxyphenyl)ethene (41). 

An alternative synthesis of 9//-tribenz.[/ >,ia, /]azepine (65, R = H) involves cycloaddition of 10,1 l-dehydro-5i/-dibenz[/t,/]azepine (66), generated from 5-acetyl-10-bromo-5//-dibcnz[/ ,/]azepine, with cyclohexa-1,3-diene.8 The cycloadduct 67, so-formed, with potassium rm-butoxide in refluxing bis(2-methoxyethyl) ether (diglyme) undergoes hydrolysis and loss of ethene to give the tribenzazepine in 39% yield. 

Treatment of a chloroform or dichloromethane solution of l-bromo-2,2-diphen-ylethene or l-bromo-2,2-bis(4/-methoxyphenyl)ethene with a slight excess of triethylsilane and a 9- to 10-fold excess of TFA gives the corresponding ethanes in 62% and 88% yields, respectively, after one hour at 0° (Eq. 123).184... 

Direct conversion of a-bromo esters into amino esters by hydride reduction of the azido ester (without isolation) produces yields in excess of 80% [7]. However, bromomalonates fail to form the azido ester under similar conditions. Instead, oxidative dimerization occurs to yield the ethene-l,l,2,2-tetracarboxylate (see Section 6.1) [10]. 

Attempts to convert 1-bromo-l-phenylacetonitrile into the dicyano derivative under liquidrliquid two-phase conditions have been unsuccessful but, on addition of aqueous sodium hydroxide, l,2-dicyano-l,2-diphenylethene is formed by an oxidative dimerization mechanism [18], Similarly, diethyl bromomalonate fails to produce the corresponding azide with lithium azide under catalytic conditions the sole product (15%) is the ethene-l,l,2,2-tetracarboxylate [19]. 

The cw-l,2-bis(diphenylphosphino)ethene complexes [Fe(Ph2PCH=CHPPh2)2X2], X = C1 or Br, undergo pressure-induced spin-state transitions at about 8kbar for the chloro complex, about 60 kbar for the bromo complex. The difference is ascribed to the difference in ligand field strengths and lattice cooperativity. ... 

The introduction of umpoled synthons 177 into aldehydes or prochiral ketones leads to the formation of a new stereogenic center. In contrast to the pendant of a-bromo-a-lithio alkenes, an efficient chiral a-lithiated vinyl ether has not been developed so far. Nevertheless, substantial diastereoselectivity is observed in the addition of lithiated vinyl ethers to several chiral carbonyl compounds, in particular cyclic ketones. In these cases, stereocontrol is exhibited by the chirality of the aldehyde or ketone in the sense of substrate-induced stereoselectivity. This is illustrated by the reaction of 1-methoxy-l-lithio ethene 56 with estrone methyl ether, which is attacked by the nucleophilic carbenoid exclusively from the a-face —the typical stereochemical outcome of the nucleophilic addition to H-ketosteroids . Representative examples of various acyclic and cyclic a-lithiated vinyl ethers, generated by deprotonation, and their reactions with electrophiles are given in Table 6. 

In a series of studies, substituents were introduced or varied at the 2-positions of the thiophene rings of di(benzothienyl)ethenes. The reactions of 3-bromo-2(n-aIkyl)-l-benzothiophene with BuLi and octafluorocyclo-pentene gave bis(2-n-alkyl-l -benzothiophen-3-yl)perfluorocyclo-pentenes 60 containing alkyl substituents with a different chain length at position 2 of the benzothiophene ring. The authors stated that the Et-, Pr-, and Bu-containing derivatives exhibit photochromic properties even in the crystalline state (06JPP(A)162). 

The reaction of 2,5-disubstituted 3-furyl bromides with butyl-lithium and octafluorocyclopentene in dry tetrahydrofuran (THF) at —78°C gave bis(furyl)ethenes 82 (06JMC4690). Photochrome 83 (05JOC10323, 06EJ03105) (29-46% yield) and a series of its derivatives 84 (55-65%) containing different substituents at position 6 of the ben-zofuran ring were synthesized from 3-bromo-2-methyl-1-benzofuran (08JPP(A)146). 

Dithienoheteroepines are readily synthesized from bis(2-bromo-3-thienyl)ethene on treatment with ferZ-butyllithium followed by the corresponding metal reagent, and readily undergo thermal decomposition to furnish benzodithio-phenes <1997H(45)1899>. Interestingly, the isomeric thienoheteroepines proved remarkably stable to thermal decomposition, presumably due to the inability to produce the required intermediate (Equation 74). 

Reaction of 1-bromo- and l-chloro-2-(4-morpholino)-l,2-diphenyl-ethene with phenyllithium in benzene to give 2-(4-morpholino)-l,2-diphenyl-ethene [202]. 

SCHEME 29. Pd- and In-cocatalyzed cross-coupling of alkenylalanes with (Ii)-l-iodo-2-bromo-ethene... 

Dehydrobrominalion of 1,2-dibromo-/V,A -bis(trifluoromethyl)ethanamine (37) and bromo-ethenes 38 (see also Section 4.1.1.) and 39 gives A, A -bis(trifluoromethyl)ethynamine (40).114115... 

Ethene 1.2-BiV[bis-(trifluorome-thyl)-iimino]-bromo- E10b2- 103 (Educt)... 

Ethene 1-Bromo-2,2-difluoro-1 -piperidino- E15/2, 2888 (F2C-C F2 + Amin/LiBr)... 

Ethene 2-Bromo-2-(3-phcnyT allyloxy)-l,1,-trifluoro- F,IOh2, 148 (Educt)... 

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