Diamination, of alkenes

A Cu(OAc)2-catalyzed intramolecular diamination of alkenes using sulfamide substrates such as compound 214 provides a route to fused thiadiazolidines 215 (Equation 48) <2005JA11250>. In this reaction, the transition metal activates the alkene toward nucleophilic attack by the first nitrogen, then becomes displaced by the second nitrogen nucleophile (a net M +z to M reduction). 

A first example of an enantioselective catalytic diamination of alkenes has been developed, which employs enantiopure titanium complexes as catalysts and bis(r- butylimido)dioxoosmium(VIII) as the nitrogen source.129... 

These monomeric and presumably tetrahedral complexes are intermediates in the diamination of alkenes (see p. 559). It is curious that, whereas 0s04 and OsQ3(NR) react with alkenes R to give square-based pyramidal dimers 0s204(02R )2 (p. 593) and [0s02 (OR (NR))]2 (p. 559) respectively, the reaction products of 0s02(NR)2 (and presumably of OsO(NR)3) with alkenes are monomeric 290 there is no obvious reason for this. It is significant that Os-—N rather than Os—O bonds are formed in these reactions.290... 

Diamination of alkenes can also be achieved intramolecularly through the nickel-catalyzed oxidation reaction, affording a wide-range of different cyclic sulfamides <07AG(E)7125>. The cyclization of sulfamide 223 proceeds in the presence of NiCU or Ni(acac)2 (10 mol%) and PhI(OAc)2 with complete selectivity, and no products other than cyclic sulfamides are observed. An initial involvement of aminometalation generates a cyclic intermediate 224. The subsequent oxidative C-N bond formation, presumably via a Ni(III) intermediate from oxidation with PhI(OAc)2, yields the bicyclic sulfamide 225. The reaction scope is well extended to the formation of spiro-cyclic sulfamides, tricyclic sulfamides and chiral substrates... 

The paUadium-promoted vicinal diamination of alkenes can be achieved according to Scheme 39 the example chosen illustrates how the mechanism and stereochonistry were determined. The independent synthesis of (36) from a qualemized aziridine is also notewordiy. Yields are 60-87% from ter-... 

The palladium-promoted diamination of alkenes has been modified to yield m-l,4-diamino-2-enes fix>m dienes (Scheme 92). ... 

Diamination of alkenes. This reaction can be effected with a primary or secondary aromatic amine (2 equiv.) and 1 equiv. of 1 in refluxing THF (4 hours). 

Oxo(/erf-alkylimido)osmium complexes are utilized in the diastereoselective oxyamination and diamination of alkenes. A mechanism involving nucleophilic attack of alkene to osmium and formation of a four-membered cyclic intermediate has been proposed38, but the [3 + 2] cycloaddition mechanism has also been suggested by quantum chemical calculations on models for hex-2-enopyranosides39. 

Vicinal Diamination of Alkenes with 1Vis(rm-Butylimido)oxoosniiuni (3) General Procedure72 ... 

Generated in situ amidoiodanes 458 and 459 are usehil reagents for metal-free direct allylic amination or diamination of alkenes [616,617]. 

General procedure for the gold-catalyzed diamination of alkene ... 

Nucleophiles other than OH also give stereospecific additions at alkenes. The acetylacetonate ion adds to co-ordinated cis- or trans-C J z in [Pd(CsH5)-(PPh3)(CHD=-CHD)]+ to give [Pd(C5H5)(PPh3) CHDCHDCH(COMe)2 ] by fra 5-addition, and the overall c/j-diamination of alkenes has been achieved by rraAZ5-aminopalladation of alkenes followed by oxidative amination in which the amine displaces the oxidized palladium by an 5 n2 displacement so that there is inversion at the Pd-bound carbon atom. Other carbon-centred nucleophiles (aryl, alkyl, or methoxycarbonyl) had previously been shown to add cis to alkenes, presumably by prior co-ordination at the metal. 

Scheme 4.10 Cyclic ureas from intramolecular diamination of alkenes, n = 1, 2.

The intramolecular diamination of alkenes could be further extended to the synthesis of cyclic guanidines (Eq. (4.29)) [31]. In this case, copper chloride represents the optimum oxidant and the reaction proceeds equally well for both five and six-membered annelation products. 

The quest for a metal-catalyzed diamination of alkenes was reahzed by Muniz, who introduced N-sulfonylated ureas 132 as nitrogen sources for this type of processes (Scheme 16.35). The reaction proceeds through two consecutive C-N bond-forming events to the cyclic ureas 138, which were investigated in detail in a mechanistic study [96]. 

In the presence of a nickel(II) catalyst, suUamates can be used as nitrogen sources for the intramolecular vicinal diamination of alkenes 141 (Scheme 16.37). While the mechanism of this oxidative transformation is not fully understood, the reaction bears the advantage that cyclic sulfamates 142 undergo selective deprotection under conventional conditions. Hence, this diamination protocol represents an attractive approach to free aminomethyl pyrrolidines (100). 

Scheme 16.40 Copper-catalyzed intra/intermolecular diamination of alkenes and enantiose-lective version.

Strict intermolecular diamination of alkenes remains a difficult process in transition-metal catalysis. Still, some interesting reactivity has recently been uncovered for terminal alkenes [122-124]. First, Shi reported the development of diamination of styrenes 18 and 179 under copper catalysis (Scheme 16.49). These protocols make use of three diaziridine derivatives 180-182, which were used as... 

Scheme 16.50 Intermolecular regioselective diamination of alkenes under Pd(ll/IV) catalysis.

The development of suitable conditions for the intramolecular diamination of alkenes using iodine(III) promoters was initially addressed by Wirth within his aminooxygenation reactions. For the case of tosylated urea precursor, the corresponding diamination product could be isolated, but a general profile towards diamination was not reported [54]. 

In the presence of oxidants, such as bromine, m-chloroperbenzoic acid (MCPBA), and V-bromosuccinimide (NBS), 50 mol % of Pd(PhCN)2Cl2 was reported to promote the diamination of alkenes with dimethylamine (eq 84). ... 

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