Hydrogen iodide adduct

For the determination of the absolute configuration of the major diastereomer of silane (5,S)-3, the hydrogen iodide adduct (5,5)-3 HI was formed by reaction of the compound with anhydrous hydrogen iodide (solution in diethyl ether) at 0 °C. Colorless needles of (5,5)-3-HI were obtained as single crystals from CH2Cl2/n-pentane. 

The photolysis of polyhalogenated compounds forms the basis for another monochrome system. Iodoform can undergo photolysis to produce hydrogen iodide, which subsequendy reacts with a di(2-furfuryl) derivative (3) and aromatic amines to produce a colored dye adduct (4) (29). The photolysis scheme and subsequent reactions can be shown by the following ... 

Hydrogen haHde addition to vinyl chloride in general yields the 1,1-adduct (50—52). The reactions of HCl and hydrogen iodide [10034-85-2], HI, with vinyl chloride proceed by an ionic mechanism, while the addition of hydrogen bromide [10035-10-6], HBr, involves a chain reaction in which a bromine atom [10097-32-2] is the chain carrier (52). In the absence of a transition-metal catalyst or antioxidants, HBr forms the 1,2-adduct with vinyl chloride (52). HF reacts with vinyl chloride in the presence of stannic chloride [7646-78-8], SnCl, to form 1,1-difluoroethane [75-37-6] (53). 

Crabtree, Johnson, and Tebby then showed that the methoxymethylindolizine, originally formulated as (109), on successive treatment with hydrogen iodide and diazomethane gave (110). The methoxymethylindolizine must, therefore, be (111) and a similar compound was obtained from 3-methylpyridine. Attempts to convert corresponding labile (77) and stable adducts (78) into (111) by... 

The addition product of ethyl acetoacetate and methyl a-methoxyacrylate was hydrolyzed, and the resulting dicarboxylic acid was treated with dimethylamine hydrochloride and aqueous formaldehyde. The product of the Mannich reaction was decarboxylated, reesterifed, and finally treated with methyl iodide to supply quaternary salt 469 as the main product. During the above one-pot process, elimination also took place, yielding unsaturated ketone 470, which was later utilized as its hydrogen bromide adduct 471. Reaction of 3,4-dihydro- 3-car-boline either with 469 or 471 furnished the desired indolo[2,3-a]quinolizine derivative 467 as a mixture of two diastereomeric racemates. 

Most alkenes do not polymerize in the presence of only hydrogen halides. One noticeable exception is JV-viny] carbazole, the most nucleophilic alkene, which is successfully polymerized by HI, HBr, and HC1 [111], Polymerization by HI produces well-defined polymers [112], Cyclohexyl vinyl ether also produces well-defined polymers when initiated by HI, although the polymerization is slow [113]. Other vinyl ethers form 1 1 a-alkoxyiodoethanes adducts with hydrogen iodide rather than polymer, especially in nonpolar solvents [Eq. (27)]. 

Interaction between alkyl halides and trialkylarsine oxides generally yields a hydrogen halide adduct, 2R3AsO,HX, with liberation of an olefin, but with triethylarsine oxide and either methyl or benzyl iodide a hydroxy iodide is produced. A similar intermediate (132) has been isolated from experi-... 

Our recent study has indicated that adducts between vinyl ethers and hydrogen iodide [CHjCHfOR)—I R = alkyl], coupled with equimolar iodine, can induce living polymerization of vinyl ethers that is virtually identical to those initiated by the HI/I2 system. Therefore, the initiation mechanism for this initiator (Eq. (27) and (28)) needs investigating further... 

As already reported (5), hydrogen iodide has been employed as an initiator that would give a nucleophilic iodide counteranion for polymerization of vinyl ethers (Eg. 3). This protonic acid, however, soon turned out to yield an adduct (3) only, without inducing any polymerization, because the polarization of the carbon-iodine bond of is too small (6). In order to activate this linkage, we added a weak Lewis acid (Y), like iodine and zinc halides (ZnX ) to a guies-cent mixture of and a vinyl ether, and then a cationic polymeriza-... 

The living cationic polymerizations discussed above are invariably based on the nucleophilic iodide counteranion (activation of the carbon-iodine terminal bond Eq. 3). It is expected, however, that similar living processes are equally possible with other counteranions that can exert, as the iodide anion does, a suitably strong nucleophilic interaction with the growing carbocation. We have in fact found the phosphate anions to meet this requirement (10). Similarly to hydrogen iodide, monoacidic phosphate esters [H0P(0)R 2 R alkyl, alkoxyl, etc.] like diphenyl phosphate ( ) form a stable adduct 5) with a vinyl ether (Eq. 5). Zinc chloride or iodide then activates the phosphate bond in 5 by increasing its polarization (as in 6), and living cationic polymerization proceeds via an intermediate (7) where the carbocationic site is stabilized by a phosphate anion coupled with the zinc halide activator. 

The phosphonyl adduct 300 reacted with a dilute solution of anhydrous hydrogen chloride in ethanol or with sodium ethoxide to afford an essentially quantitative yield of the P-N cleaved product 304 with inversion of configuration. Addition of sodium ethoxide to a solution of 304 in methanol resulted in the formation of enantiomerically pure (+)-(.V)-ethyl methyl phenylphosphonate (305). It also reacted quantitatively with methylmagnesium iodide at room temperature to give the product of P-S bond cleavage 306, which upon acid catalyzed methanolysis afforded enantiomerically pure (+)-(R)- methyl methylphenylphosphinate (307) (Scheme 72) [108],... 

N-Methylethylamine has been prepared by heating ethyl-amine with methyl iodide in alcohol at 100° 3 by the hydrolysis of N-methyl-N-ethylarenesulfonamides,4-5 -nitroso-N-methyl-N-ethylaniline,6 or methylethylbenzhydrylidene ammonium iodide 7 by catalytic hydrogenation of ethyl isocyanate or ethyl isocyanide 8 and by the reduction of ethyl isocyanate by lithium aluminum hydride,9 of N-methylacetisoaldoxime by sodium amalgam and acetic acid,10 or of a nitromethane/ethylmagnesium bromide adduct by zinc and hydrochloric acid.11... 

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