Synthesis of propargylic amines
A copper(I) complex of i-Pr-pybox-diPh efficiently catalyzes the enantioselective one-pot three-component synthesis of propargylamines from aromatic aldehydes, anilines, and alkynes. A transition-state model has been proposed.
A. Bisai, V. K. Singh, Org. Lett., 2006, 8, 2405-2408.
A wide range of chiral propargylamines can be prepared in a one-pot three-component reaction between an alkyne, an aldehyde and a secondary amine at room temperature in the presence of CuBr and (R)-quinap in good yield and good enantioselectivity.
N. Gommermann, C. Koradin, K. Polborn, P. Knochel, Angew. Chem., 2003, 115, 5941-5944.
A metal-free decarboxylative three-component coupling reaction was developed. When alkynyl carboxylic acids, paraformaldehyde, and amines were reacted in CH3CN at 65 °C for 3 h, the desired propargylamines were obtained in good yields. This coupling reaction also showed good yield in water solvent. This reaction showed higher selectivity toward alkynyl carboxylic acids than a terminal alkyne.
K. Park, Y. Heo, S. Lee, Org. Lett., 2013, 15, 3298-3301.
A single Cu(II) catalyst couples a diverse range of nitrogen sources with various alkynes and aldehydes without the addition of ligand or base. Copper-catalyzed alkynylation involving p-toluenesulfonamide provides high yields of N-Ts-protected propargylamines. The superior activity of copper(II) triflate also allows this three-component alkynylation to incorporate a ketone.
C. E. Meyet, C. J. Pierce, C. H. Larsen, Org. Lett., 2012, 14, 964-967.
An economic and practical transformation from secondary alkyl-substituted propargyl acetates to a variety of nucleophilic substitution products is catalyzed by inexpensive InCl3. High yields and excellent chemoselectivity were obtained. Five-, six-, and seven-membered propargyl cycloethers were also successfully constructed.
M. Lin, L. Hao, X.-t. Liu, Q.-z. Chen, F. Wu, P. Yan, S.-x. Xu, X.-l. Chen, J.-j. Wen, Z.-p. Zhan, Synlett, 2011, 665-670.
Microwave-assisted conditions enabled a simple, rapid, one-pot synthesis of arylaminomethyl acetylenes in very good yields using arylboronic acids, aqueous ammonia, propargyl halides, copper(I) oxide and water as the solvent within ten minutes.
Y. Jiang, S. Huang, Synlett, 2014, 25, 407-410.
A simple Re2O7-catalyzed direct dehydrative coupling between π-activated alcohols with electron-deficient amines has been achieved under mild and open flask conditions. The protocol alows the conversion of allylic, benzylic, and propargylic alcohols. The mechanistic proof for the SN1-type process has also been provided.
B. G. Das, R. Nallagonda, P. Ghorai, J. Org. Chem., 2012, 77, 5577-5583.
An oxidative amination of allenes using a single hypervalent iodine reagent proceeds very efficiently for monosubstituted allenes and leads to formation of the corresponding propargylic amines, either as the internal or as the terminal amine depending on the addition of triphenylphosphine oxide to the iodine(III) reagent.
N. Purkait, S. Okumura, J. A. Souto, K. Muņiz, Org. Lett., 2014, 16, 4750-4753.
A one-pot catalyst-free chemoselective synthesis of N-benzyl propargylamines with good functional group compatibility involves in situ formation of an active amine through Petasis reaction of primary amines, formaldehyde solution, and boronic acids, which reacts in a decarboxylative coupling reaction with propiolic acids to give products in high yields.
H. Feng, H. Jia, Z. Sun, J. Org. Chem., 2014, 79, 11812-11818.
A highly enantioselective, catalytic three-component coupling of aldehydes, alkynes, and 4-piperidone hydrochloride hydrate affords the corresponding tertiary propargylamines in useful yields. A selective cleavage of the piperidone protecting group is possible using either ammonia/EtOH or a polymer-supported scavenger amine.
P. Aschwanden, C. R. J. Stephenson, E. M. Carreira, Org. Lett., 2006, 8, 2437-2440.
A highly efficient gold-catalyzed three-component-coupling of aldehydes, alkynes, and amines in water was developed. Excellent yields of the corresponding propargylamines were obtained in most cases for both aromatic and aliphatic aldehydes and various amines.
C. Wei, C.-J. Li, J. Am. Chem. Soc., 2003, 125, 9584-9585.
A three-component coupling between an aldehyde, alkyne and amine is catalyzed by silver iodide to generate propargylic amines in high yields in water without cocatalyst or activator. This method is especially effective for reactions involving aliphatic aldehydes.
C. Wei, Z. Li, C.-J. Li, Org. Lett., 2003, 5, 4473-4475.
A three-component coupling reaction of alkynylsilanes, aldehydes and amines produces a variety of propargyl amine derivatives by a cooperative catalytic system comprised of CuCl and Cu(OTf)2. This catalytic system was successfully applied to the practical preparation of 1,6-diyne derivatives via twice-performed, domino-type coupling reactions.
N. Sakai, N. Uchida, T. Konakahara, Synlett, 2008, 1515-1519.
Propargylamines have been synthesized by a gold(III) salen complex-catalyzed three-component coupling reaction of aldehydes, amines, and alkynes in water in excellent yields at 40°C. With chiral prolinol derivatives as the amine component, excellent diastereoselectivities have been attained.
V. K.-Y. Lo, Y. Liu, M.-K. Wong, C.-M. Che, Org. Lett., 2006, 8, 1529-1532.
A general and efficient FeCl3-catalyzed substitution reaction of propargylic alcohols with carbon- and heteroatom-centered nucleophiles such as allyl trimethylsilane, alcohols, aromatic compounds, thiols, and amides, forms new C-C, C-O, C-S and C-N bonds.
Z.-P. Zhan, J.-L. Yu, Y.-Y. Cui, R.-F. Yang, W.-Z. Yang, J.-P. Li, J. Org. Chem., 2006, 71, 8298-8301.