Aryl derivatives

Aryl Derivatives.—The Ph3P=N group imparts high nucleophilic reactivity to the tervalent phosphorus atom in A -(diphenylphosphino)tri-phenylphosphazene, Ph3p=N PPha- Ready reactions occur with methyl iodide, phosphorus(in) halides, and bromine  

With phosphorus trichloride, a rather complex reaction results partly in the formation of [PhaP N uPPha PPhCl]+ Cl. The reactivity of the phosphorus(iii) atom is also demonstrated by its ability to desulphurize thiophosphoryl chloride, and its ready reactions with Group VI elements, diborane, and carbon disulphide  

With carbon disulphide a betaine-type structure PhaPiiiNiiiPPha—C(S)S, may be formulated for the reaction products. The P n.m.r. spectra of these compounds were discussed in detail. 

The reactions of triphenylphosphazenyl derivatives with many other electrophilic species have been described. With sulphur tetrafluoride, sulphur imines are formed, possibly via the four-centred intermediate (24)  

With cobalt(ii) chloride, complexes of the monophosphazene, PhgP=NH (= L), of stoicheiometry CoCl2L,THF and C0CI2L2 have been isolated. Their i.r. and u.v. spectra were compared with analogous complexes of triphenylphosphine oxide. 

4 Aryl derivatives. Crystal structures were reported for (i) 

The thermal stability of o-ClCgH.Li is markedly increased on the addition of TMED. Benzo[b]thiophene (ArH) and Na provide the 2- 

The lack of o,o -dilithiation of PhCONEt, even with excess Bu Li. 

was emphasisedj 2,6-Li2CgH CONEt2 is available from 2,6- 

7 Aryl derivatives. Enthalpies of solvation of 2-ROCgH Li and 8-Li-l-MeO-naphthalene in BugO are lower than those of the 4-lithio isomers by ca. 20 and 28 kJ moT respectively. 

The closest L1...H contacts in 2-Li-l-Ph-pyrrole (18) involves in both solution (as found using 6 Li- H 2D heteronuclear Overhauser NMR spectroscopy) and in the solid state [from a crystal structure determination of (18. TMED)g  

Two simple phenyl derivatives have been studied by low-temperature XD phenylcyclo-propane (41) at -100°C and m-l,2-diphenylcyclopropane (42) at -40°C (Table 4). Structural data of 43 are also listed in the Table. 

TABLE 4. Bond lengths (A) and bond angles (deg) of phenylcyclopropane (41), m-l,2-diphenylcyclopropane (42) and trans-1 -cyano-2-phenylcyclopropanc (43) from XD  

Parameters of the phenyl ring have been calculated from atomic coordinates and unit cell parameters given in the paper. eOpposite to the perpendicular Ph group. 

The effect of the cyano substituent seems to dominate in 43 the bond opposite to it is the shortest91. The C—C (N) bond has the same length, 1.447 (4) A, as in other cyanocyclo-propanes (Section III.D). The phenyl group adopts the bisected conformation. Crystallization leads to a spontaneous resolution, which is rather rare among phenylcy-clopropanes, and a conglomerate of chiral crystals is formed91. 

The antiestrogenic activity of 47a motivated structural studies of gem-dichloro compounds 479. The orientations of the m-diaryl rings in 47 and in the well-known 

Two independent molecules are found in the monoclinic Pa crystal of 41, both in the bisected form. The distal bond in the cyclopropane ring is shorter by 0.018 A than the vicinal bonds. The phenyl groups of 42 are rotated (as calculated from atomic coordinates) by 19 and -85° from the bisecting position, away from each other. Such conformation-ally asymmetric molecules make up the chiral orthorhombic crystals. The phenyl 

The aluminium-chloride-catalysed Friedel-Crafts phenylation of chloro-dimethylaminocyclotriphosphazatrienes NgPaCle-n n = 1,2 (two isomers), and 3 (three isomers)] occurs more rapidly at =PClNMe2 groups than at 

The appearance of virtual coupling effects in the n.m.r. spectra of the two geminal isomers of N4p4(NMe2)4Ph4, (43) and (44), has enabled them to be 

Octahedral chromium(m) chelate complexes CrLa (45), CrL2(acac), and 

CrL(acac)2 (acac = acetylacetonate) have been obtained from the ligand Ph2P(0)NHP(0)Ph2. 

Two general reviews on this topic have been previously noted.  

In solid [3-l-2-Li-l-methylindole.2THF]2, lithium atoms bridge ipso carbons and each is additionally coordinated to two THF ligands. The compound, [ 2,6- 

As shown by C, Li coupling constants and multiplicities in the NMR spectra, vinyl-lithium exists in a dimer-tetramer equilibrium in THF. The tetramer undergoes an intra-aggregate C-Li bond exchange process. A comprehensive analysis of the NMR spin-spin coupling constants was made. The Jc c values in vinyl-lithium were determined to be very small,viz 35.0 Hz for the dimer and 36.3 Hz for the tetramer. 

The crystal structure of the carbenoid [(p-ClC6H4)2C=CClLi.TMED.THF].THF has been determined at -115 C Li is bonded to C, O and 2N. Of interest, the C-Cl bond in (7) [1.855(7) A] is much longer than that in non-lithiated vinyl chlorides (average value 1.729 A). The preparation of (Z)-LiCH=CHC6H4Li-o from reaction of (Z)-LiCH=CHPh and Bu Li/TMED has been reported. H and C NMR spectral studies of H2C=CH-CH(Li)SiMe2CH2N(CH2CH20Me)2 in THF and toluene indicate an equilibrium mixture of endo- and exo-silyl species in which Li is tridentately complexed to the 

Dilithio species, [Li(TMED)]2[o-C6H4CH2B(NR)CH2], (10) obtained fiom lithiation of 2-R2N-2-boraindanes, have triple decked structures consisting of aromatic 1 On-electron 2-benzoborole dianions and two [LiCTMED)] moieties facially bonded to the horole ring. ° 

The crystallisation of potassium fluorenide or 9-Bu -fluorenide from a mixture of THF, TMED and EtjO yielded [F1K(TMED)2] or [K(THF)2][ ii-9-Bu Fl][K(TMED)][p.-9-Bu Fl] (11). Both complexes were characterized by X-ray crystallography and by NMR spectroscopy (11) has a polymeric chain structure with K coordinated to two 6-membered rings from two bridging 9-Bu F1 units.  

The simple structures of THF-solvated 2,6-di(l-naphthyl)phenyllithium and 2,6-di(phenyl)phenyhithium have been reported to be respectively mono- and dinuclear. The solid-state structure of (DME Li)2C4(SiMc3)4 has recently been found to incorporate DME-chelated metal centres above and below a four-membered, flat cyclobutadienyl ring (within which mean O-C = 1.495 A). A similar structure has also been revealed for (DME Li)2C4Ph2(SiMe2CH2)2. The two electron reduction of 2,3-bis(dimethylsilyl)-l,l,4,4-tetramethyl-l,4-disila-1,4-dihydronaphthalene using elemental lithium affords a complex in which the two metal centres bridge an isolated C = C bond. In the same way, alkali metal ions reside above and below each of two C=C interactions in the tetrametal salt which results from the treatment of 2,3,6,7-tetrakis(trimethylsilyl)-l,l,4,4,5,5,8,8-octamethyl-1,4,5,8-tetrasila- 1,4,5,8-tetrahydroanthracene with Li(0).  

The derivatisation of both 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol and its 3,5-di-tert-butyl congener as mono- and dimeric lithium and sodium aryloxides has afforded structures in which the metal ions are supported by weak interactions with the 4-methylphenoxide ring. Moreover, evidence for interactions between sodium or potassium ions and aromatic n-systems has recently formed the basis of a review article.  

The triple-decker coordinative behaviour of fullerene trianions has been probed by reducing Ceo in 18-crown-6 using potassium metal. Lately the syn- 

Just as Bu Li has recently been probed by Li solid-state NMR speetroscopy, so too have a variety of alkyl- and aryllithium oligomers been studied with a near linear relationship between Li quadrupolar eoupling [x( Li)] and C Li-C angle being revealed.  

The host behaviour of a 1,3-alternate calix-bis-crown has been studied in the solid state and has already been discussed. However, on a related theme, it has recently been established that in solution ealix[4]arene-crown eompounds act as hosts for alkali metals and that subsequent cation-rr interactions are responsible for changes in the fluorescenee bands of the host the fluoreseenee quantum yields of such complexes have been shown to decrease as the alkali metal component is made larger.  

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Very small quantities of bismuthine are obtained when a bismuth-magnesium alloy, BijMgj, is dissolved in hydrochloric acid. As would be expected, it is extremely unstable, decomposing at room temperature to bismuth and hydrogen. Alkyl and aryl derivatives, for example trimethylbismuthine, Bi(CHj)3, are more stable. 

Pseudo-saccharin ethers. When pseudo-saccharin chloride is heated with an excess of a phenol, 0-aryl derivatives of saccharin are produced (compare Section 111,27, 7). 

Alkylselenazoles are oily alkaline liquids possessing a smell similar to that of the corresponding thiazole or pyridine derivatives. The crystalline picrates or 3-methylselenazolium iodides have been used for the purpose of characterization. Alkyl derivatives are partially soluble in water aryl derivatives are insoluble. 

With the exception of the nuclear amination of 4-methylthiazole by sodium amide (341, 346) the main reactions of nucleophiles with thiazole and its simple alkyl or aryl derivatives involve the abstraction of a ring or substituent proton by a strongly basic nucleophile followed by the addition of an electrophile to the intermediate. Nucleophilic substitution of halogens is discussed in Chapter V. 

The 5-aryl derivatives have been prepared in a similar way from substituted phenylbromoacetonitrile (239), R = phenyl, X = Br. 

Organometallic compounds contain a carbon-metal bond They are named as alkyl (or aryl) derivatives of metals... 

Ketenes c=c=o 2060-2040 (vs) 1130 (s) 1374 (s) 1120 (s) Pseudo-asymmetric stretching Pseudo-symmetric stretching Alkyl derivatives Aryl derivatives... 

Mass spectral fragmentation patterns of alkyl and phenyl hydantoins have been investigated by means of labeling techniques (28—30), and similar studies have also been carried out for thiohydantoins (31,32). In all cases, breakdown of the hydantoin ring occurs by a-ftssion at C-4 with concomitant loss of carbon monoxide and an isocyanate molecule. In the case of aryl derivatives, the ease of formation of Ar—NCO is related to the electronic properties of the aryl ring substituents (33). Mass spectrometry has been used for identification of the phenylthiohydantoin derivatives formed from amino acids during peptide sequence determination by the Edman method (34). 

Ai lepiesents an aiyl group. Diaiyl products are obtained after long reaction times. Other Friedel-Crafts catalysts, eg, ZnCl2, FeCl2, FIF, and BF, can also be used. In most cases, stoichiometric amounts of the catalyst ate requited. Flowever, strong complexation of the phosphine by the catalyst necessitates separation by vacuum distillation, hydrolysis, or addition of reagents such as POCl to form more stable aluminum chloride complexes. Whereas yields up to 70—80% are possible for some aryl derivatives, yields of aliphatic derivatives are generally much less (19). 

The addition of 2,2, 4,4, 6-pentanitro-6 -methyldiphenylamine [64653-47-0] to seawater precipitates potassium (38). Aromatic amines, especially aminotetrahydronaphthalenes and their A[-aryl derivatives, are efficient flotation agents for quartz. The use of DPA for image formation in films has been patented (39,40). Diarylamines are used as intermediates (41) for azo, sulfur, oxidative base, triaryhnethane, oxazine, nitro, and safranine dyes (see Dyes and DYE INTERLffiDIATES). 

The A/-alkyl and W-cyclohexyl derivatives of sulfamic acid are comparatively stable. The A/-aryl derivatives are very unstable and can only be isolated ia the salt form. A series of thia2olylsulfamic acids has been prepared. 

Thiophene [110-02-1] and a number of its derivatives are significant in fine chemical industries as intermediates to many products for pharmaceutical, agrochemical, dyestuffs, and electronic appHcations. This article concentrates on the industrial, commercial, and economic aspects of the production and apphcations of thiophene and thiophene derivatives and details the main synthetic schemes to the parent ring system and simple alkyl and aryl derivatives. Functionalization of the ring and the synthesis of some functional derivatives that result, not from the parent ring system, but by direct ring cyclization reactions are also considered. Many good reviews on the chemistry of thiophene and thiophene derivatives are available (1 7). 

The first -PDA antiozonants were low molecular weight -diaLkyl-/)-PDAs which caused skin irritations. Current higher molecular weight -dialkyl or A/-alkyl-AT-aryl derivatives are not primary skin irritants. A notable exception is A/-(I-methylethyl)-A7-phenyl-/)-PDA, which causes dermatitis. However, since some individuals are more sensitive than others, antiozonants should always be handled with care (46). When skin contact does occur, the affected area should be washed with mild soap and water. In case of eye contact, flush weU with water. Inhalation of mbber chemicals should be avoided, and respiratory equipment should be used in dusty areas. 

IV-Alkyl substituted ureas usually eliminate the IV-substituted amine (80JHC235), but IV-arylthioureas may give ring IV-aryl derivatives 66UC447). 

The glycidyl adducts are skin irritants similar in behaviour in this respeet to the parent amines. The skin sensitisation effects in the primary aliphatic amine may be reduced by addition of groups at the nitrogen atom. The hydroxyethyl group and its alkyl and aryl derivatives are the most effective found so far. 

Since this bloom is brittle, it is broken by flexing. Therefore, waxes only protect under static conditions. For serving conditions which involve continuous flexing, /j-phenylenediamines (A, A -alkyl-aryl derivatives) can be added. These chemical antiozonants scavenge the ozone before it reacts with the rubber. A barrier of ozonized products is created which protects both the rubber and antiozonant from further attack. However, p-phenylenediamines are staining compounds. Whenever colour is an important concern, blends of elastomers can be used elastomers loading should be higher than 30 phr to provide sufficient effectiveness. 

The insertion of calcium atoms into vinyl and aryl carbon-fluorine bonds has been reported Only the resulting organometallic from the aryl derivatives appears to live long enough to be trapped by water [J]... 

It is notable that the preparation of alkyl and aryl derivatives from Pb starting materials always results in Pb organometallic compounds. The only well-defined examples of Ptf ... 

Stabilization of /j -alkyl and -aryl derivatives of transition metals can be enhanced by the judicious inclusion of various other stabilizing ligands in the complex, even though such ligands are known not to be an essential prerequisite. Particularly efficacious are potential IT acceptors (see below) such as AsPh3, PPh3,... 

Corresponding aryl derivatives are rare and unstable. Thus, while AuMe3 decomposes above —35°C but is stabilized in [AuMe3(PPh3)J, AuPh3 is unknown. 

Alkyl and 6-aryl derivatives of 3,5-dioxo-2,3,4,5-tetrahydro-l,2,4-triazine or of its thio analogs have been mentioned before in this review (e.g., Section II,B,2,a). Some of theih contained functional... 

Heating arylamines with carbon dioxide at 200 C (8500 atm) gives good yields of 3-aryl derivatives of 2,4-dihydroxyquinazoline ° (see 5e). The method is unsatisfactory when riitro, halo, and phenolic anilines and a- or p-naphthylamines are used. 

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