A Convenient Synthesis and Some Characteristic Reactions of Novel Propiolamidinium Salts

Abstract

Starting from N,N,N′,N′,N′′,N′′-hexaalkylguanidinium chlorides and terminal alkynes, a series of new orthoamide derivatives of alkynecarboxylic acids were prepared. The orthoamides were converted into propiolamidinium chlorides by reaction with benzoyl chloride and into propiolamidinium triflates by reaction with triethylsilyl trifluoromethanesulfonate. Propiolamidinium salts undergo conjugate addition reactions with sec-amines and thiols­. Treatment of terminal alkyne chlorides with silver(I) oxide afforded a silver complex, which can apparently adopt the composition of either a bisalkynyl silver complex [Ag(CCC(NMe₂)₂)₂]AgCl₂ or a monoalkynyl silver complex [ClAgCCC(NMe₂)₂].

Key words

alkynes - amidinium salts - orthoamides - hexamethyl­guanidinium chloride - silyl triflates

References

• For selected references for cycloaddition reactions, see:
• 1a Nikolai J. Schlegel J. Regitz M. Maas G. Synthesis  2002,  497 
• 1b Gerster H. Espenlaub S. Maas G. Synthesis  2006,  2251 
• 1c Gerster H. Maas G. Z. Naturforsch., B  2008,  63:  384 
• For selected references for reaction with nucleophiles, see:
• 2a Maas G. Mayer T. Synthesis  1991,  1209 
• 2b Reinhard R. Glaser M. Neumann R. Maas G. J. Org. Chem.  1997,  62:  7744 
• 2c Schlegel J. Maas G. J. Prakt. Chem.  2000,  342:  235 
• 2d Reisser M. Maier A. Maas G. Eur. J. Org. Chem.  2003,  2071 
• 2e Reisser M. Maas G.
  J. Org. Chem.  2004,  69:  4913 
• 2f Rahm R. Espenlaub S. Werz UR. Maas G. Heteroat. Chem.  2005,  16:  437 
• 3a Viehe HG. Baum JS. Chimia  1975,  29:  300 
• 3b Baum JS. Viehe HG. J. Org. Chem.  1976,  41:  183 
• 3c François J.-P. Gittos MW. Synth. Commun.  1979,  9:  741 
• 4 Baum JS. Postdoctoral Technical Report   UCL Louvain; Belgium: 1975. 
• 5 Kantlehner W. Lehmann H. Stahl T. Kaim W. Chem.-Ztg.  1991,  115:  183 
• 6 Eilingsfeld H. Neubauer G. Seefelder M. Weidinger H. Chem. Ber.  1964,  97:  1232 
• 7 Hobbs CF. Weingarten H. J. Org. Chem.  1971,  36:  2881 
• 8 Kantlehner W. Speh P. Lehmann H. Bräuner HJ. Haug E. Mergen WW. Chem.-Ztg.  1990,  114:  176 
• 9a Hobbs CF. Weingarten H. J. Org. Chem.  1971,  36:  2885 
• 9b Kantlehner W. Haug E. Stieglitz R. Frey W. Kress R. Mezger J. Z. Naturforsch., B  2002,  57:  399 
• 10 Midland M. J. Org. Chem.  1975,  40:  2250 
• 11 Kantlehner W. Kreß R. Mezger J. Ladendorf S.
  Z. Naturforsch., B  2005,  60:  227 
• 12 Weingarten H. Tetrahedron  1968,  24:  2767 
• 13a Jutz Ch. Müller E. Angew. Chem.  1966,  78:  747 
• 13b Art J.-F. Janousek Z. Viehe HG. Synth. Commun.  1990,  20:  3031 
• 14 Maas G. Würthwein E.-U. Singer B. Mayer T. Krauss D. Chem. Ber.  1989,  122:  2311 
• 15 Asay M. Donnadieu B. Schoeller WW. Bertrand G. Angew. Chem. Int. Ed.  2009,  48:  4796 ; Angew. Chem. 2009, 121, 4890
• 16 Wang HMJ. Lin IJB. Organometallics  1998,  17:  972 
• 17 Rais D. Yau J. Mingos DMP. Vilar R. White AJP. Williams DJ. Angew. Chem. Int. Ed.  2001,  40:  3464 ; Angew. Chem. 2001, 113, 3572
• 19 Kantlehner W. Vettel M. Lehmann H. Edelmann K. Stieglitz R. Ivanov IC. J. Prakt. Chem.  1998,  340:  408 
• 20 Kantlehner W. Haug E. Mergen WW. Speh P. Maier T. Kapassakalidis JJ. Bräuner H.-J. Hagen H. Liebigs Ann. Chem.  1984,  108 
• 21 Marino JP. Nguyen HH. J. Org. Chem.  2002,  67:  6841 

18

Details of the crystal structure analysis of 11b will be reported elsewhere. The bond lengths in the organic part of the complex suggest a rather small degree of electron delocalization toward the bond structure of a [bis(dimethylamino)allenylidene] silver(I) complex (compare lit.^¹5).