Tosyl amide

Aminopalladation and subsequent carbonylation are also facile reactions. The carbonylation of substituted 3-hydroxy-4-pentenylamine as a carbamate (254) proceeds smoothly via the aminopalladation product 255 in AcOH to give 256[228). The protection of the amino group of the carbamate as tosyl amide is important in the carbonylation of 257 to give 258[229],... 

Sml2, DMPU, 50-97% yield. " The reaction works well for alkyl-substituted aziridines benzenesulfonamides react faster than tosyl amides. 

Li, catalytic naphthalene, -78°, THF, 97-99% yield. In addition, tosyl-amides and mesylamides are cleaved with similar efficiency. 

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. 

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)... 

This method accommodates aryl aldehydes with both electron-deficient and electron-rich aryl substitutents. Acetaldehyde is also a competent couphng partner, providing the corresponding amido ketone in 62% yield. Acyl substitution of the tosyl amide varies to include hydrogen, methyl, tert-butoxy, and phenyl producing the desired a-amido ketones in moderate to high yields. Expansion of this methodology to synthesize di- and tri-substituted imidazoles was reported by Murry and co-workers (Scheme 7) [54]. 

The palladium-catalyzed ring heteroannulation of allenes 278 by tosyl amide and amine-containing allyl and vinyl halides (e.g., 277) provided a facile route to a variety of azepanes (e.g., 279) (Equation 39) <2003JOC6859> in the case of iV-tosyl-(2-iodophenyl)ethylamine, benzazepines are formed. 

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. 

This method provided an efficient access to cyclopentylamine-containing alkaloid skeleta. Similarly, by using 1-propynyl phenyliodonium triflate and various tosyl-amide anions, the preparation of dihydropyrroles and indoles was reported [72]. 

The recent synthesis of furans via isomerization of terminal epoxyalkynes catalysed by RuCl(Tp)(MeCN)2 in the presence of a base at 80 °C in 1,2-dichloroethane is explained by a related intramolecular nucleophilic addition of the oxygen atom of the epoxide onto the a-carbon atom of a ruthenium vinylidene intermediate (Scheme 8) [33]. This reaction is specific of terminal alkynes and tolerates a variety of functional groups (ether, ester, acetal, tosyl-amide, nitrile). 

The unusual 1,2,3-benzoxathiazole (14) was prepared by Tl(III) oxidation of the bis(tosyl-amide) of 4-bromobenzene-l,2-diamine treatment of the sulfonamidines (188) with KOBu to give the 1,2,3-oxathiazolines (189) is a related reaction. 

For the addition, carboxylic amides, tosyl amides, carbamates and A-substituted ureas were employed (Table 1)20 22. 

Oxaziridines are converted to ring-expanded lactams under photochemical conditions. A-Tosyl aziridines with an a-hydroxyalkyl substituent give a pinacol rearrangement product in the presence of Lewis acids, such as Sml2> in this case a keto-A-tosyl amide. ... 

In the first step, formyl ketone 14a reacts via its enol form 14b with tosyl azide in a 1,3-dipolar cycloaddition yielding intermediate 15. Its triazoline ring resolves into the a-diazo ketone 4 and 7V-formyl tosyl amide. 

The basicity of cesium carbonate is strong enough to deprotonate tosyl amides [38]. Although lithium, calcium, and rubidium carbonates have also been examined for use of the same reaction for cyclization of ditosyl amide, they do not work efficiently compared with cesium carbonate (Scheme 2.23). Cesium carbonate is also important base for the preparation of calix[4]arenes and carcerands [39]. 

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-... 

Mori et al. have shown that asymmetric alkylation with an allylic tosyl amide followed by a zirconium-promoted cyclization provides an efficient route to mesembrine and mesembrane alkaloids [107]. The best ee was obtained with BINAPO as the ligand. Scheme 28. The product was obtained in 86% ee and following recrystallization the sulfonamide was obtained in 99% ee. 

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."... 

Allyl tosyl amides. Reaction of all) the corresponding halides (in situ) with amides. 

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