N-Tosyl amides

Similarly, acyclic co-olefmic N-tosyl amides with vinyl bromides have also been used to give pyrrolidones and piperidones in 49 to 82 % yield (eight examples) [54]. 

N-Tosyl amides and lactams.2 DCC in combination with 4-pyrrolidinopyri-dine (4-PPy) effects condensation of carboxylic acids with secondary sulfonamides to provide N-tosyl amides in 75-90% yield. The intramolecular version of this reaction provides 4-, 5-, and 6-membered N-tosyl lactams in 60-90% yield. 

Halolactamization.3 Unsaturated amides generally form lactones when cyclized by Br2 or I2. However the unsaturated N-tosyl amide I, when treated with Br2 in the presence of N a HC03, forms the bromo N-tosyl /J-lactam 2 (67%yield). Dehalogenation of 2 is best effected with Bu3SnH. 

The cyclization product 142 has the desired absolute configuration for the alkaloids 137-139 and was transformed as described in Scheme 27. Thus, condensation of 142 with acid chloride 147 gave N-tosyl amide 148. This compound underwent intramolecular Heck cyclization to yield tetracycle 149 which is a derivative of (+)-lycoricidine (138). 

N-Tosyl amides. Carboxylic acids react with TsN=C=0 to afford RCONHTs. These amides can be transformed into thioesters in two step A-methylation (Mel, K2CO3, DME) and treatment with RSH."... 

As part of the total synthesis of the neurotoxin (-(-pumiliotoxin C [69], Minnaard and coworkers [70] used a domino Mizoroki-Heck/Tsuji-Trost reaction as the key step to prepare the perhydroquinoline 124 in 26% yield from 122 and 123 after hydrogenation (Scheme 8.31). Similarly, acyclic vinyl bromides have been used to give the corresponding lactams in 49-82% yield [71]. 

The N—CO distance of 1.38 A in (58) is rather greater than that of a normal amide (ca. 1.32 A) this has been attributed to ring strain and to inhibition of normal amide resonance by interaction with the N-aryl substituent. This inhibition of resonance is more pronounced in the N-tosyl-4-thioxoazetidin-2-one (59), which exhibits very short C=0 and C=S distances as well as the unusually long C—N bonds (80TL4247). NMR investigations... 

Metathesis of N-tosylated ene-amides and yne-amides has been less extensively investigated. An example of the RCM of ene-amides is a new indole synthesis developed by Nishida [79] metathesis precursor 96 (prepared by ruthenium-catalyzed isomerization of the corresponding allyl amide) is cy-clized to indole 97 in the presence of 56d (Eq. 13). 

The compound R2CuLi also adds to N-tosylated a,P-unsaturated amides Nagashima, H. Ozaki, N. Washiyama, M. Itoh, K. Tetrahedron Lett., 1985, 26, 657. 

C-nucleophile (X = active H-borate, boronate) N-nucleophile (amine, NaN3, tosyl amide, amide, lactam, imine, carbamate, urea) O-nucleophile (alcohol, acid, carbonate) S-nucleophile (PhS02Na)... 

Itoh reports that copper-catalyzed Grignard additions to N-tosyl-N-alkyl-a.p-unsaturated amides and N-tosyl-a,(3-unsaturated lactams proceed efficiently while deprotonation occurs exclusively with the corresponding A/-alkyl-a,(3-unsaturated lactams (Scheme 45).94... 

This purely ionic class of compounds has several members they are prepared from amides of carboxylic acids and PhI(OMe)(OTs) in acetonitrile, at room temperature as N-phenyliodonio amide tosylates (Scheme 21) [66]. 

Tetrakis(dimethylamino)titanium is a useful reagent for preparing amidines from secondary amides. From A X-thionyldiimidazole and secondary amides of boA aromatic and aliphatic carboxylic acids amidines (313 Scheme 50) are formed under mild conditions in moderate to good yields. N-Tosyl-amidines (314) can be obtained by reacting secondary thioamides (aliphatic and aromatic) with tosyl azide. Thiobenzamides have been condensed with anilines to afford amidines (315). Thioamides can be converted to amidines, e.g. (316), by treatment with ammonia in the presence of mercury acetate. ... 

In analogy to the synthesis of iminium salts (Section 4.2.2.1.), acyiiminium ions (60) can be obtained from carbonyl precursors (1), such as ketones or aldehydes, and carboxylic acid amides (62 Scheme 30). In addition, other amides can be used, such as p-toluenesulfonamides, which lead to the corresponding N-tosylated iminium salts. ... 

The synthesis of ( )-pancratistatin (211) has been achieved by application of a sequence of the reactions noted previously to a [Z-O-t-butyldimethylsilyl (TBS)-4,5-methylenedioxy]phenyl derivative. Namely, coupling of N-(p-tosyl)aziridine 232 with the cuprate derivative of [3-0-TBS-2-(A(,N-dimethylcarboxamido)-4,5-methylenedioxy]benzene, in a manner similar to that noted for 210, produced N-(6-arylcyclohex-4-enyl)-N-(p-tosyl)amide as a mixture of atropisomers, reductive N-... 

Two series of reactions were carried out on this compound. In one of these, the tosyl amino alcohol 418 was reacted with /3-chloropropionyl chloride followed by oxidation with Jones reagent to give the tosyl keto amide 419. Elimination of HC1 with potassium carbonate in methylene chloride and cyclization of the acrylamide with Meerwein s reagent gave the N-tosyl keto lactam 420. This compound was also prepared by the previously discussed route (203). 

The vinylogous amide lactam 411 prepared by the route described previously (203) was N-tosylated in 44% yield by reaction with sodium hydride in boiling monoglyme followed by treatment with tosyl chloride. On treating the tosyl derivative 428 with excess acrylonitrile in tert-butanol-dimethyl sulfoxide in the presence of potassium re/t-butoxide, two products were formed the pentacylic derivative 429 and the hexacyclic compound 430. Further base treatment of the former compound gave 430 in quantitative yield, thereby bringing the overall reaction yield to a respectable 50%. 

CAS 80-39-7 1077-56-1 EINECS/ELINCS 201-275-1 214-073-3 Synonyms N-Ethyl-p-methylbenzene sulfonamide N-Ethyltoluene-2-sul-fonamide Ethyl p-toluenesulfonamide Ethyl to amide (INCI) p-Tolu-ene ethylsulfonamide N-Tosyl ethylamine Classification Mixture of isomers of aromatic amides En firical CsHnNOjS Formula C2H5NHS02CeH,CH,... 

Pb-tetraacetate added with stirring at room temp, to a soln. of tosyl amide in dimethyl sulfoxide, warmed 0.5 hr. at 50°, triethylamine added, and the product isolated after an additional hr. N-tosyldimethylsulfoximine. Y 61. F. e., also sulfonylsulfilimines from sulfonamides and tbioetbers, s. T. Ohashi et al.. Synthesis 1971, 96. 

Unsaturated amides are suitable substrates for elaboration by addition of carbon nucleophiles. N-tosylated a,B-unsaturated... 

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