Compounds N-vinyl

Similarly, pyrrole, indole, and tetrahydrocarbazole [285] as well as diarylamines give the corresponding N-vinyl compounds [286]. Several improvements of yields and reaction rates were observed by conducting the reactions in the presence of additives [287, 288]. The vinylation of imidazole and benzimidazole was reported to be catalyzed by KOH in the presence of zinc or cadmium salts [289]. The above reactions were reviewed in 1965 [290]. 

Greater differences between the optical activity of monomers and of polymers have been recently observed by Schulz and Hartmann 133) when investigating the free-radical and ionic polymerization of a number of variously substituted N-vinyl compounds. The above authors also observed in one case a large dependence of the optical activity of the polymers on the type of solvent used. 

Systems with higher sensitivities can be obtained by addition of N-vinyl compounds in which the vinyl group is directly attached to the nitrogen atom. N-vinylcarbazole is a preferred compound. A latent image formed upon a short exposure is developed to a high-density image by heating (146). 

Although N-vinyl compounds are the starting materials for the synthesis of several important polymers, a convenient and general method of synthesis is not known. In the presence of catalytic amounts of NaPdCU, however, cyclic iV-vinyl compounds are formed in good yield (ca. 80%) by the reaction of imides and lactams with vinyl acetate [equation (20)]." ... 

Molybdenum n -vinyl compounds arise in the reactions of LiBHBu 3, LiCuAr2 or LiCuMe2 reagents with various alkyne complexes. THese are described as either n, 3 electron vinyls or metallacyclopropenes. Insertion of alkynes into the M=C bond of... 

Reppe, W. and E. Keyssner. 1935. N-Vinyl compounds. Germany Patent 618,120. 

Chloromethylbenzo-l,2,4-thiadiazine 1,1-dioxide forms quaternary salts, e.g. 8 (n = 1), with pyridine, 2- and 3-picolines, and iso-quinoljne, but the 3-(2 -chloroethyl) compound gives a lower yield of the salt, e.g. 8 (% = 2), because some of the halogen derivative is converted into the 3-vinyl compound. ... 

An additive described as reducing the water loss and enhancing other properties of well-treating fluids in high-temperature subterranean environments consists of polymers or copolymers from N-vinyl lactam monomers or vinyl-containing sulfonate monomers. Organic compounds like lignites, tannins, and asphaltic materials are added as dispersants [175]. 

There are reactive softeners, some of which are N-methylol derivatives of long-chain fatty amides (10.241) while others are triazinyl compounds (10.242). The N-methylol compounds require baking with a latent acid catalyst to effect reaction, whereas dichloro-triazines require mildly alkaline fixation conditions. The N-methylol compounds are sometimes useful for combination with crease-resist, durable-press, soil-release and water-repellent finishes. In this context, the feasibility of using silane monomers such as methyltri-ethoxysilane (10.243), vinyltriethoxysilane (10.244), vinyl triace tylsilane (10.245) and epoxypropyltrimethoxysilane (10.246) in crosslinking reactions to give crease-resist properties and softness simultaneously has been investigated [492]. 

This method for preparing 2-phenyl-1-pyrroline, and assorted 2-substituted 1-pyrrolines, is one of the best currently available, particularly because it reproducibly affords clean materials. Generally, the procedure is amenable to various aromatic esters 2 it has also been applied successfully to aliphatic esters (Table I).3 An advantage of this method is the use of readily available, inexpensive N-vinyl-pyrrolidin-2-one as a key starting material. This compound serves effectively as a 3-aminopropyl carbanion equivalent. The method illustrated in this procedure has been extended to include the synthesis of 2,3-disubstituted pyrrolines. Thus, alkylation of the enolate of the intermediate keto lactam, followed by hydrolysis, leads to various disubstituted pyrrolines in good yields (see Table II).3... 

The unusual annulation of a substituted phenyl ring through [4 + 2] cycloaddition of vinyl compound 59 with dimethyl acetylenedicarboxylate (DMAD) as dienophile affords indolo benzazepine 60 in 53% yield, while a similar reaction with N-methyl-maleimide or maleic anhydride yields tetracyclic 61a,b in 53-87% yield (Scheme 12 (2003T6659)). 

The polymerization of monosubstituted vinyl compounds that give polymers like PS and PP produces polymer chains that possess chiral sites on every other carbon in the polymer backbone. Thus, the number of possible arrangements within a polymer chain is staggering since the number of possible isomers is 2" where n is the number of chiral sites. For a relatively short chain containing 50 propylene units the number of isomers is about 1 x lO. While the presence of such sites in smaller molecules can be the cause of optical activity, these polymers are not optically active since the combined interactions with light are negated by other similar, but not identical, sites contained on that particular and other polymer chains. Further, it is quite possible that no two polymer chains produced during a polymerization will be exactly identical because of chiral differences. 

A number of highly reactive dihalogenides 118,120, and 122, far too reactive to be synthesized by conventional techniques, have been quantitatively obtained in pure form by halogen gas addition to solid N-vinyl and S-vinyl compounds at the appropriate temperatures [33,61,74] (Scheme 13). 

Another very instructive case concerns the alleged initiation of a cationic polymerisation by a charge-transfer complex formed by the compound chloranil (2,3,5,6-tetrachloroquinone) with the monomer N-vinyl-carb-azole. It was shown (Natsuume et al., 1969 1970) that this compound is not an initiator, but that the polymerisations were caused by a hydrolysis product, 2-hydroxy-3,5,6-trichloroquinone, which is a strong acid. One has learnt from this finding to be extremely suspicious of any claims for charge-transfer catalysis and to test one s suspicions by appropriate experiments involving progressive purification of the putative catalyst. 

N-Vinylpyrroles are one of the universal types of reactive carriers of the pyrrole moiety which can be used for different purposes in organic synthesis and polymerization. However, even in the early 1970s, they were considered (74MI1) to be almost unknown and unavailable compounds. Indeed, except for the comparatively well known N-vinyl derivatives of... 

Clearly, there is a fine balance between [2 + 2]- and [4 + 2]-cycloaddition in the reaction of TCNE with vinylindoles. The cycloaddition of 1-methyl-3-vinyl compound and TCNE in benzene gives mainly the [4 + 2]-product, although a small amount of the [2 + 2]-adduct also appeared to be formed. In liquid sulfur dioxide this [4 + 2]-adduct completely isomerized to the [2+ 2]-product. It is probable that in the reaction between diene 205 and TCNE the transition state for [4 + 2]-cycloaddition is destabilized by the steric requirements of the bulky N-benzyl group. 

Methods for the conversion of derivatives of morphine into their N-nor-com-pounds, using vinyl chloroformate,149 trichloroethyl chloroformate,150 and phenyl chloroformate,151 have been patented. Norneopine has been prepared from neopine and diethyl azodicarboxylate and by the hydrolysis of 7V-nitrosonor-neopine.152 The conversion of N-nor-bases into N-alkyl-compounds by the reduction of amides has been covered by a further patent.153... 

The N-vinyl-azole class, in which the 1-N atom of the azole is directly bonded to an sp2-hybridized carbon of a substituted olefin, belongs to the relatively recently synthesized subgroup of bioactive azoles. Compounds of this nature can be obtained by condensation of aldehydes with triazolyl-pinacolone resulting in a mixture of the E and Z isomers of the corresponding a, f3 -unsaturated ketones. Borohy-dride reduction easily converts these ketones into the corresponding alcohols (9)(Figure 16). 

Mahanty, f. S. De, M. Kundu, N. G. Palladium-catalyzed heteroannulation of vinylic compounds a highly convenient method for the synthesis of N-aryl-l,2,3,4-tetrahy-dro-l-oxoisoquinoline-3-carboxylic adds. 

---