N acetyl indoles

Excellent ee-values (up to 94%) have been obtained for the hydrogenation of various 2-substituted N-acetyl indoles with an in-situ prepared rhodium catalyst modified with the trans-chelating diphosphine (S,S)-(R,R)-2,2"-bis[l-(diphenyl-phosphino)ethyl]-1,1"-biferrocene (Scheme 16.23) [88]. A strong base was required as co-reagent to observe both high conversion (TOFs of 50-100) and en-... 

There are reports of an increasing number of palladium-assisted reactions, in some of which the palladium has a catalytic function. Thus furan and thiophene undergo facile palladium-assisted alkenylation giving 2-substituted products. Benzo[6]furan and N- acetyl-indole yield cyclization products, dibenzofurans and carbazoles respectively, in addition to alkenylated products (81JOC851). The arylation of pyrroles can be effected by treatment with palladium acetate and an arene (Scheme 86) (81CC254). 

Isolation and structural characterization of a-N-acetyl-indole-3-acetyl-e-L-lysine a new metabolite of indole-3-acetic acid from Pseudomonas syringae pv savastanoi. Phytochemistry 24 1499-1502. 

Derivatives 30 (R OH, R2 = iV-acetyl-indol-3-yl-(CH2)2 and (R = OEt, R2 = Ph-(CH2) (n — 2, 3)) were transformed into intramolecular Friedel-Crafts type reactions involving A-acyliminium cation intermediates into the cis-and trans-isomeric mixtures of the corresponding fused derivatives on treatment with strong acid <2000TL2745, 2001JOC5731>. 

Prior to his work with internal alkynes, Larock found that o-thallated acetanilide undergoes Pd-catalyzed reactions with vinyl bromide and allyl chloride to give (V-acetylindole and N-acetyl-2-methylindole each in 45% yield [409]. In an extension to reactions of internal alkynes with imines of o-iodoaniline, Larock reported a concise synthesis of isoindolo[2,l-a]indoles 313 and 314 [410]. The regioselectivity was excellent with unsymmetrical alkynes. 

TRYPTAMINE, N-ACETYL-5-METHOXY INDOLE, 3-(2-ACETAMIDOETHYL)-5-METHOXY SEROTONIN, N-ACETYL-O-METHYL ACETAMIDE, N-[2-(5-METHOXYINDOL-3-YL)ETHYL] N-ACETYL-5-METHOXYTRYPTAMINE 3-(2-ACETAMIDOETHYL)-5-METHOXYINDOLE N-ACETYL-O-METHYLSEROTONIN N-[2-(5-METHOXYINDOL-3-YL)ETHYL]ACETAMIDE REGULIN... 

Since the duration of the process is limited by the environment of the phosphorus atom, completion of the reaction in the case of dipropoxyphenylphosphonite required 2.5 h (160-170°C), while in the case of tripropyl phosphite it required 6 h. N-Acetyl(phosphoryl)indole 158 is also produced in the Michaelis-Becker reaction from N-chloroacetylindole and sodium diethyl phosphite [160]. 

Some selected examples of 7c-barriers are given in Table XII. Conformational states of N-acetyl derivatives of pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, indole, benzimidazole, benzotriazole, indazole, and tetrazole have been studied by 13C NMR (78JCS(P2)99). In some cases, the occurrence of only one isomer precludes the determination of the barrier, as for 1-acetylpyrazole (74BSF1137) and 1-acetylindoles (750MR445). 

Mercuriation of indole by mercuric acetate in acetic anhydride is accompanied by N-acetylation, giving 61% of l-acetyl-3-acetoxymercuriin-dole. The 2- and 3-methyl derivatives of indole and of benzo[b]seleno-phene are substituted in the 3- and 2-positions, respectively [70CHE254 71CHE1401 72CHE18],... 

Acyl-pyrroles, -furans, and -thiophenes in general have a similar pattern of reactivity to benzenoid ketones. Acyl groups in 2,5-disubstituted derivatives are sometimes displaced during the course of electrophilic substitution reactions. /V-Alkyl-2-acy I pyrroles are converted by strong anhydrous acid to A-alkyl-3-acylpyrroles. Similar treatment of N-unsubstituted 2- or 3-acylpyrroles yields an equilibrium mixture of 2- and 3-acylpyrroles pyrrolecarbaldehydes also afford isomeric mixtures. The probable mechanism of these rearrangements is shown in Scheme 133. A similar mechanism has been proposed for the isomerization of acetyl indoles. 

Finally, ortho- 2,2-dibromovinyl)-aniline or -acetanilide can successfully be applied in a sequential cyclizing amination-cross coupling reaction with diethyl phosphonate to furnish the indolyl phosphonic ester 136 or the N-acetyl 2-aryl indole 137 as recently shown by Bisseret and coworkers [ 105] (Scheme 50). This sequence can be also performed with corresponding phenol derivatives furnishing benzofurans. For the N-acetyl 2-aryl indole 137 it can be shown that the Suzuki coupling occurs prior to the intramolecular animation as a consequence of the gradual difference in reactivity between trans-and czs-carbon-bromine bonds. 

N-acetyl derivatives of these products along with unspecified amounts of Indole were also formed. Further irradiation of the products converted them in high yield into the corresponding indoles. Photo-Fries rearrangement of... 

Reactions of this type have been used in the synthesis of indoles on a solid phase [143, 144]. Yamazaki et al. described a combination of palladium-catalyzed amination and Heck reaction in a synthesis of indole [145]. One indole synthesis is performed by a Heck reaction of N-acyl dehydroalanine immobilized on REM resin (24) -with 1-2 halobenzenes (26). In the case of 2-N-acyl-aminocinnamoyl esters, the N-acetyl groups gave higher yields than CBz-groups and 1,2-dibromo-benzene (78%) was more efficient than l-bromo-2-triflyloxybenzene (41%) (Scheme 3). 

The asymmetric hydrogenations of N acetyl, N carbamate, and N sufonyl indoles are asymmetric hydrogenations of enamides. not imines, and will therefore not be covered here. For reports of this reaction, see (a) Kuwano, R. and Kashiwabara. M., (2006) Org. Lett., 8,... 

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