Intramolecular C−N Bond Addition of Amides to Alkynes Using Platinum Catalyst

Abstract

The intramolecular aminoacylation of alkynes using ortho-alkynylacetanilides proceeds in very high yields in the presence of PtCl2 catalyst. This reaction provides not only a useful procedure for synthesizing 2,3-disubstituted indoles at once from ortho-alkynylaniline derivatives, but also an interesting mechanistic aspect; the intramolecular C-N bond addition of amides to alkynes takes place readily in the presence of Pt(II) catalyst.

Construction of indole nucleus through C-H functionalization reactions

“…Alkyne 22a was converted into indole through application of an intramolecular platinum-catalyzed aminoacylation reaction. 91 A strong primary kinetic isotope effect was observed for the C-H bond activation. Additionally, the stoichiometric reaction of an acetanilide-derived palladacycle similar to compound 23 with bromoacetylene also generated the o-alkynyl aniline 22.…”

π-Conjugated carbocycles and heterocycles via annulation through C-H and X-Y activation across CC triple bonds

“…Platinum(II)-catalyzed intramolecular aminoacylation of alkyne of ortho-alkynylamides 8 (CR′ 3 = acyl) produced indoles having 3-CR′ 3 substituent 9 (Scheme 3). 73,74 In the case of 8 (CR′ 3 = CH 2 OMe), that means, in the case of N,O-acetal instead of amide group, the Pt(II)-catalyzed reaction also produced indoles 9 having 3-CH 2 OMe group. -substituted indoles 9, in which the alkenyl group originated from R of alkyne.…”

Stabile cyclische Carbene und verwandte Spezies jenseits der Diaminocarbene

“…Yamamoto et al [115] berichteten über Platin-und Palladium-katalysierte intramolekulare C-N-Additionen von Amiden und N,O-Acetalen und Cacchi et al [116] über die Palladium-katalysierte Cyclisierung von 2-Alkinyl-N-allyl-N'-trifluoracetylbenzolamin. normalerweise Gemische, in denen die thermodynamischen Produkte überwiegen: mehr E-als Z-Isomere, mehr interne als terminale Olefine (Ethenolyse).…”