With Phenyl Halides

Unlike alkyl halides, phenyl bromide and iodide reacted only sluggishly with diaryl telluriums. The neat reagents had to be heated at 150° for 40 h to obtain moderate yields of triaryl telluronium halides.  

Dimethyl tellurium, however, reacted with phenyl iodide at 20° to produce dimethyl phenyl telluronium iodide in 50% yield .  

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Phosphanions with Phenyl Halides in Liquid Ammonia ... 

Trichlorogermane does not react with phenyl halides and naphthyl halides. This is again indicative of the electrophilic nature of the interaction between trichlorogermane and the aromatic compounds. 

The main feature of carbanions derived from nitriles lies in the dependence on the aromatic substrate involved thus, two different outcomes of the substitution reaction are possible formation of the substitution compound by ET to the substrate from the radical anion intermediate 7, formed by coupling of phenyl radicals and acetonitrile anion, or formation of products from elimination of the cyano group as is the case with phenyl halides [31,32] (Sch. 3). The same reactivity pattern is found with halothiophenes [33]. 

As previously indicated, monoanions of / -dicarbonyl compounds fail to react with phenyl halides however, the 1,3-dianions are suitable nucleophiles and react quite well through the terminal carbanion site185. 

Glueck and co-workers studied in detail the Pd-catalysed enantio-selective coupling of bulky racemic secondary phosphines with phenyl halides (Scheme 6.23). 

The topic of special interest is to develop cross-coupling methodology to carry out the reaction between ArX and RSH in water in the absence of organic ligands. Recently, it was reported that thiophenol reacts with phenyl halides in water in the presence of Bu+NBr (TBAB) at 80 °C (Scheme 3.40) [73]. Product yields in the reaction... 

Reaction with Phenyl Halides Phenyl Iodide Method 1... 

Anilides and a-Naphthalides. The Grignard reagents prepared from alkyl halides react with phenyl isocyanate (CgHjN=C=0) or with a-uaphthy l isocyanate (C,oH, N=C=0) to yield addition products that are converted by hydrolysis into anihdes and a-naphthalides respectively RX + Mg —> RMgX... 

A special problem arises in the preparation of secondary amines. These compounds are highly nucleophilic, and alkylation of an amine with alkyl halides cannot be expected to stop at any specifle stage. Secondary amides, however, can be monoalkylated and lydrolyzed or be reduced to secondary amines (p. 11 If.). In the elegant synthesis of phenyl- phrine an intermediate -hydroxy isocyanate (from a hydrazide and nitrous acid) cyclizes to pve an oxazolidinone which is monomethylated. Treatment with strong acid cleaves the cyclic irethan. 

The reaction of a halide with 2-butene-1,4-diol (104) affords the aldehyde 105, which is converted into the 4-substituted 2-hydroxytetrahydrofuran 106, and oxidized to the 3-aryl-7-butyrolactone 107[94], Asymmetric arylation of the cyclic acetal 108 with phenyl triflate[95] using Pd-BINAP afforded 109, which was converted into the 3-phenyllactone 110 in 72% ee[96]. Addition of a molecular sieve (MS3A) shows a favorable effect on this arylation. The reaction of the 3-siloxycyclopentene 111 with an alkenyl iodide affords the. silyl... 

Many examples of insertions of internal alkynes are known. Internal alkynes react with aryl halides in the presence of formate to afford the trisubstituted alkenes[271,272]. In the reaction of the terminal alkyne 388 with two molecules of iodobenzene. the first step is the formation of the phenylacetylene 389. Then the internal alkyne bond, thus produced, inserts into the phenyl-Pd bond to give 390. Finally, hydrogenolysis with formic acid yields the trisubstituted alkene 391(273,274], This sequence of reactions is a good preparative method for trisubstituted alkenes from terminal alkynes. 

Aryl and alkenyl phenyl sulfides are prepared by the reaction of aryl and alkenyl halides and inflates with tributylstannyl phenyl sulfide. 2-Chloropyrimidine (737) is used for the coupling[606,607]. The diaryl or divinyl sulfide 739 is prepared by the reaction of distannyl sulfide (738)[548], N,N-Diethylaminotributyltin (740) reacts with aryl halides to give arylamines[608]. 

The lack of a uniform order of relative reactivity of the halogens in reactions of certain nucleophiles with nitro- and polynitro-phenyl halides led Parker and Read to propose a one-stage mechanism for some aromatic nucleophilic substitutions. An alternative explanation within the framework of the two-stage S Ar2 mechanism had been proposed earlier. A range of mechanisms has been considered in the past by Chapman, who properly points out that only in a limited number of examples is the evidence for the two-stage mechanism compelling even though the balance of evidence favors it. 

Phenyl-V-heptene Typical Procedure for the Reaction of RCu BE, with Allylic Halides and Allylic Alcohols 11 ... 

In this section indirect methods will be explored. One was given in Section 3.6. There, data were presented for two members of a large family of reactions of the phenyl radical with organic halides. Pairs of halides were used, and the ratio of two competing products was determined. Expanding the general scheme of Eq. (5-1) further, to use a pair of competing traps, we have... 

The anion of DMSO undergoes a phenylation reaction with aryl halides under sunlight stimulation38. The presence of benzhydryl methyl sulfoxide (maximum yield 5%) in all runs, the sunlight activation, the order of reactivity of halobenzenes (I > Br > Cl), the inhibition of the reaction with oxygen, all hint at the SRN139-44 mechanism (Scheme 3). 

Tertiary aliphatic amines are also cleaved by HI, but useful products are seldom obtained. Tertiary amines can be cleaved by reaction with phenyl chloroformate R3N -h ClCOOPh —> RCl 4- R2NCOOPh. a-Chloroethyl chloroformate behaves similarly.Alkyl halides may be formed when quaternary ammonium salts are heated R4N+X" R3N -)- RX. ... 

Allylic silanes react with aldehydes, in the presence of Lewis acids, to give an allyl-substituted alcohol. In the case of benzylic silanes, this addition reaction has been induced with Mg(C104)2 under photochemical conditions. The addition of chiral additives leads to the alcohol with good asymmetric induction. In a related reaction, allylic silanes react with acyl halides to produce the corresponding carbonyl derivative. The reaction of phenyl chloroformate, trimethylallylsilane, and AICI3, for example, gave phenyl but-3-enoate. ... 

Trippett and Stewart have shown that the phosphonium salts (11) derived from the reaction of phenyl di-t-butylphosphinite (12) with alkyl halides are highly resistant to hydrolysis and they suggest that this is due to the reluctance of phosphorus to accommodate two t-butyl groups in a trigonal-bipyramidal intermediate. 

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