Alkynes amination

Keywords alkyne, amine, paraformaldehyde, alumina, Mannich condensation, microwave irradiation, aminoalkyne... 

As a supporting evidence, it is well-known that the electron-rich 0 6-arene)Ru complex of terminal alkyne 428 rearranges easily by the treatment with NaPR, of the )/ -vinylidenc complex 429, which is a strongly electrophilic carbene complex. Attack of ROH on the carbene carbon generates the the alkoxycarbene complex 431 via 430 [166]. Formation of ketone 427 by attack of the allylic alcohol is understanable by this mechanism. Formation of Ru-vinylidene complex 429 from the terminal alkyne has been proposed as the intermediate 432 of the reaction of terminal alkyne, amine and CO2 to form the vinyl carbamate 433 [167,168]. 

REACTIONS CATALYZED BY COPPER, SILVER, OR GOLD 12.2.1 Aldehyde-Alkyne-Amine Coupling... 

Halides are second only to carboxylic acids in their versatility in organic synthesis. Functional group transformations into alkenes, alkynes, amines, aldehydes, alcohols, ethers, hydrocarbons, ketones and other groups may be performed with ease in high yield. However, the major synthetic importance of halides arises from the ease by which compounds that contain this functionality may be used in carbon-carbon bond-forming reactions and in the preparation of heterocyclic compounds. 

Wei C, Li Z, Li CJ (2004) The development of A -coupling (aldehyde-alkyne-amine) and AA -coupling (asymmetric aldehyde-alkyne-amine). Synlett 1472-1483 Bariwal JB, Ermolat ev DS, Van der Eycken EV (2010) Efficient microwave-assisted... 

The electropilic phosphinidine complex 29 can be generated in situ by the reaction of dichloro(diisopropyl-amino)phosphine with Collman s reagent. By trapping reactions with various alkynes, amine-substituted phosphirene complexes 30 are accessible (Equation 24) <2000T137>. 

The reaction is carried out by slowly adding the 1-bromoalkyne to a solution containing the terminal alkyne, amine, copper(i) chloride and hydroxylamine hydrochloride. The amine, usually ethylamine, is used in excess, e.g. 1-8 moles/mole of alkyne, and catalytic quantities (1-5 mol %) of copper(i) chloride are used. One of the side-reactions is the self-coupling of the bromoalkyne induced by Cu(i) which in turn is oxidized to Cu(ii) (equation 11). The hydroxylamine salt serves to reduce the copper back to the cuprous state. 

Another ruthenium-catalyzed oxidation uses tetrapropylammonium permthenate (TRAP) [24]. Being a ruthenium(VII) oxide, the permthenate ion is a less powerful oxidant than rutheni-um(VIII) oxide and more functional groups are stable to the oxidation conditions, including alkenes, alkynes, amines, amides, benzyl, trityl and silyl ethers [24]. However, alcohols and lactols still undergo oxidations in high yield with W-methyl-morpholine A-oxide (NMO) as the stoichiometric oxidant. The reactions are usually carried out in dichloromethane, acetonitrile, or mixtures of both in the presence of molecular sieves [24]. 

Alkylrheniumoxides are known to be versatile, highly active and efficient catalysts for the oxidation of various organic substrates such as olefins, alkynes, amines, ketones, sulfides, or metal carbonyls (a) Hoechst AG (W. A. Herrmann, D. W. Marz, J. G. Kuch-ler, G. Weichselbaumer, R. W. Fischer) DE 3.902.357 (1989) (b) W. A. Herrmann,... 

Figure 12 Proposed transition states for the formation of diastereomeric syn and anti alkynic amines in reactions...

Amidine synthesis. Alkynes, amines, and suUbnylazides (or phosphoryl azides) are combined to generate amidines. The alkynes and/or the amines can he functionahzed, and their use leads to amidines containing an a-amino group or a phosphoranylalkyl group, when starting from ynamides and imidophosphoranes, respectively. 

A synthesis of a-substituted acrylamides from l-alkynes, amines and carbon monoxide based on catalysis by Pd(OAc)2-DPPP is carried out in (bmim)NTf2. ... 

Naphthylamines have been prepared by the cross-coupling of terminal alkynes, amines, and bromoketones, presumably through the corresponding acetylenic enamine (Eq. 22) [56]. 

Rebolledo, F. Brieva, R. Gotor. V Tetrahedron Lett., 1989, 30, 5345. SECTION 305 ALKYNE AMINE... 

A stirred soln. of startg. mercaptal in 9 1 methanol/water treated with (CF3C02)2lPh, and stirred at room temp, for 2 min 6-acetoxyhexanal. Y 85%. The method is mild, rapid, and leaves a variety of functional groups unaffected esters, nitriles, secondary amides, alcohols, halides, alkenes, alkynes, amines, and thioesters. F.e., also acetals in pure alcoholic media, s. G. Stork, K. Zhao, Tetrahedron Letters 30, 287-90 (1989). 

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