Imines alkynes

The analytical data obtained, particularly by the PUMA mass spectrometer on board Vega 1 during the flyby, indicate the presence of a large number of linear and cyclic carbon compounds, such as olefins, alkynes, imines, nitriles, aldehydes and carboxylic acids, but also heterocyclic compounds (pyridines, pyrroles, purines and pyrimidines) and some benzene derivatives no amino acids, alcohols or saturated hydrocarbons are, however, present (Kissel and Krueger, 1987 Krueger and Kissel, 1987). 

Hi) Alkyne-alkyne (vi) Alkene-imine (vii) Alkyne-imine... 

Under the conditions of iridium-catalyzed hydrogenation, alkyne-carbonyl and alkyne-imine reductive coupling occurs in the absence of stoichiometric byproducts. For example, iridium-catalyzed hydrogenation of nonconjugated alkynes in the presence of ot-ketoesters delivers the corresponding a-hydroxy esters in... 

For enantioselective copper catalyzed addition of organozinc reagents to imines, see [97-116]. Enantioselective Ni-catalyzed alkyne, imine, triethylborane 3-component coupling has been reported, but modest selectivities (51-89% ee) are observed. For this method, vinylation is accompanied by ethyl transfer [149]... 

The intermolecular cycloaddition of an electron-deficient species such as a nitrene, a nitrenium ion or a carbene (or their formal equivalents) to the ir-bond of an alkene, alkyne, imine, or nitrile is a significant approach to aziridines and azirines (Scheme 2). 

Jamison has reported the unprecedented nickel-catalyzed assembly of allylic amines 156 from three simple starting materials alkynes, imines, and trialkylbor-anes or boronic acids. The participation of boronic acids in this methodology greatly enhances its synthetic potential, owing to their greater availability (Scheme 8.68) [145]. An asymmetric version of the reaction has also been developed but gave only moderate enantiomeric excesses (33 to 42%). 

Patel and Jamison [40] reported a catalytic three-component coupling of alkynes, imines, and triethylborane using a Ni complex and (S)-(+)-(neomenthyl)diphenyl-phosphane [(S)-NMDPP] 159 forming the alkylative coupling product (Scheme 9.28). No yields were reported. 

Scheme 9.28. Ni-catalyzed enantioselective coupling of alkynes, imines, and triethylborane.

Imido zirconocenes see Imide Complexes) are synthesized from thermolysis of Cp2Zr(Me)NHR. They react with a wide variety of organic substrates (alkynes, imines, azides, carbodiimides, ketones) to yield [2 + 2] cycloaddition products (Scheme 4) see Metallacycle) ... 

The enantioselective alkyne-imine addition has been achieved using a copper(i)-bis(oxazoline) compound in [G4GiIm]N(GF3S02)2 (Scheme 46). ... 

Chiral allylic amines constitute key synthetic intermediates, auxiliaries, and resolving agents in the synthesis of both natural and nonnatural products. In 2004, Jamison and Patel reported the first highly enantioselective catalytic synthesis of allylic amines from alkynes, imines, and organobo-ranes such as triethylborane. Catalysed by a chiral complex derived from Ni(cod)2 and chiral ferrocenylphosphine [R)-27, this novel three-component process provided chiral tetrasubstituted allylic amines in good yields in one-pot (Scheme 4.27). These products were obtained in moderate to very good enantioselectivities of up to 89% ee. Both symmetrical and... 

Dhawan, R. and Arndtsen, B.A. (2004) Palladium-catalyzed multicomponent coupling of alkynes, imines. and add chlorides a direct and modular approach to pyrrole synthesis. Journal of the American Chemical Society,... 

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