Copper-catalyzed imidations

Further examples of the functionalization of sulfur compounds with iodine(III)-nitrogen ylides include copper-catalyzed imidations of phenyl benzyl sulfide with [(sulfonylimino)iodo]benzenes possessing imidazole and pyridine rings in the sulfonyl moiety [34], and uncatalyzed tosylimidations of diaminothiocarboxylate inner salts 26 (Scheme 14) with Phi = NTs to give 27 [35]. 

OpticaUy active iV-tosylsulfoximides produced in the copper-catalyzed reaction of chiral sulfoxides with tosyl azide may be hydrolyzed with strong acid (H2SO4) to optically active free sulfoximides. However, this procedure often fails and/or results in decomposition. It is interesting to note in this connection that a simple one-step method for the preparation of optically active unsubstituted sulfoximides has been reported recently by Johnson and co-workers (180). It involves the reaction between optically active sulfoxides and 0-mesi-tylsulfonylhydroxylamine and results in sulfoximides 60 of high optical purity. As expected, this imidation process occurs with retention of configuration at sulfur. 

Savarin, C., SrogI, J., Liebeskind, L. S. A Mild, Nonbasic Synthesis of Thioethers. The Copper-Catalyzed Coupling of Boronic Acids with N-Thio(alkyl, aryl, heteroaryl)imides. Org. Lett. 2002,4, 4309-4312. 

Several phenyliodonium imides 465 derived from heteroarenesulfonylamides have been synthesized from (diacetoxyiodo)benzene and the respective amides 464 (Scheme 2.134) [630], Imides 465 can be used as sources of the corresponding heterocycle-containing nitrenes in the copper-catalyzed aziridination and sulfimidization reactions. 

Copper-catalyzed (stoichiometric or catalytic) at room temperature and weak base under air Wide scope of substrates alcohols, amides, amines, anilines, azides, hydantoins, hydrazines, imides, imines, nitroso, phenols, pyrazinones, pyridones, purines, pyrimidines, sulfonamides, sulfinates, sulfoximines, thiols, thiourea, ureas, and sulfonylguanidines... 

Catalytic Nitrene Transfer to Heteroatoms. The experimental procedure described above for the copper-catalyzed aziridination of olefins can be applied to the imidation of sulfides, where CuOTf in conjunction with PhI=NTs mediates the formation of siilfimides in good yields (eq 95). Spontaneous [2,3] sigma-tropic rearrangements occur in the case of allylic sulfides. Chiral bis(oxazoline)-CuOTf complexes catalyze both reactions with acceptable enantioselectivities (eq 96). Chloratnine-T is also a suitable but less efficient nitrene precursor. Selenides undergo the same catalytic asymmetric imidation to afford selenimides albeit with lower yields and enantioselectivities. ... 

A facile access to A-sulfonylimidates and their synthetic utility for the transformation to amidines and amides, (b) E. J. Yoo, S. H. Park, S. H. Lee, S. Chang, Org. Lett. 2009, 11, 1155-1158. A new entry of copper-catalyzed four-component reaction facile access to a-aryl P-hydroxy imidates. (c) R. Husmann, Y. S. Na, C. Bohn, S. Chang, Chem. Commun. 2010, 46, 5494—5496. Copper-catalyzed one-pot synthesis of a-functionalized imidates. (d) W. Song, W. Lu, J. Wang, P. Lu, Y. Wang, J. Org. Chem. 2010, 75, 3481-3483. A facile route to y-nitro imidates via four-component reaction of alkynes with sulfonyl azides, alcohols, and nitroolefins. (e) G. Murugavel, T. Punniyamurthy, Org. Lett. 2013, 15, 3828—3831. Novel copper-catalyzed multicomponent cascade synthesis of iminocoumarin aryl methyl ethers. 

X. Ye, C. Xie, Y. Pan, L. Han, T. Xie, Org. Lett. 2010, 12, 4240 243. Copper-catalyzed synthesis of a-amino imides from tertiary amines Ugi-type three-component assemblies involving direct functionalization of sp C-Hs adjacent to nitrogen atoms. 

The success of bis(oxazoline)-copper(II) catalyzed Diels-Alder reactions involving acryloylimides as dienophiles has been extended to the Michael reaction, Eqs. 204 and 205. The observed enantiofacial discrimination in the Diels-Alder reactions was expected to translate well to Michael reactions involving enolsilanes as nucleophiles. Indeed, fumarate-derived imides afford Michael adducts of enolsilanes in high enantioselectivity (240). Diastereoselectivity in these reactions may be regulated by judicious choice of thioester and enolsilane geometry to provide either diastereomer in high selectivity (>99 1 syn or 95 5 anti). 

More detailed mechanistic studies have been conducted with isolated ligated copper complexes, along with kinetic studies on reactions catalyzed by complexes of diamine ligands. These studies have shown that copper(I) amidate and imidate complexes are competent to be intermediates in the catalytic coupling of aryl halide with amides and imi-des. These studies also implied that two-coordinate anionic cuprate complexes undergo oxidative addition of the aryl halide more slowly than do related three-coordinate, neutral copper complexes containing a bidentate dative ligand. This conclusion is shown clearly by the formation of coupled product from iodotoluene and the species that equilibrates between the ionic and three-coordinate neutral species (Equation 19.119) and the lack of... 

Enantioselective imidation of alkyl aryl sulfides with A -alkoxycarbonyl azides as a nitrene precursor is effected by using (OC)Ru(salen) complex as catalyst. The steric and electronic nature of the Af-alkoxycarbonyl group strongly affect the enantioselectivity and the reaction rate. In a systematic and well-executed study of ligand effects on Lewis-acid-catalyzed Diels-Alder reaction, it has been shown that the attachment of aromatic a-amino acid ligands to copper(II) ions leads to an increase in the overall rate of the Diels-Alder reaction between 3-phenyl-l-(2-pyridyl)-2-propene-l-one (Din) and cyclopentadiene... 

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