[(α‐Imino)enamino]phosphonium salts from propyne iminium salts and a phosphorane imine

Abstract

ABSTRACT:

Cu(I)-catalyzed coupling reactions of fluorinated imidoyl halides with terminal alkynes: Convenient synthesis of fluorinated alkynyl imines

“…A variety of imidoyl halides with different substituents on the benzene ring were employed in this transformation. Electron-donating groups (Table 1, Entries 2,4,5,7,9,15,16,19,and 21) or weak electron-withdrawing groups (Table 1, Entries 3,6,8,10,11,12,14,17,18,19,20,and 22) on the benzene ring of imidoyl halides were compatible with the former giving better yields. But in the case of imidoyl halides with strong electron-withdrawing groups (NO 2 , F, and CF 3 ) on the benzene ring, the imidoyl chlorides shall be used as starting materials, since the corresponding imidoyl iodides is not stable in this reaction system, in such case, stoichiometric amount of CuI is needed (Table 1, Entries 3,6,8,12,18,and 20).…”

“…(100); IR (neat, cm À1 ): 2936,2218,1751,1617,1485,1377,1220,1156,1116,1092,1035,880,835,800 169.7, 147.8, 144.1 (t, J C,F = 28.9 Hz), 134. 5,130.0,127.3,120.9,119.5,114.4 (t,J C,F = 306.7 Hz),95.9,75.0,51.5,20.4; MS (EI) m/z (%): 363 (M + , 2.7), 43 (100); IR (neat, cm À1 ): 2936,2224,1756,1587,1570,1469,1219,1157,1121,907,835 7, 140.0, 139.8 (t, …”

Synthesis and reactivity of 3-(dialkylamino)allenyl phosphonium salts. PPh3-mediated synthesis of pyrroles from propyne iminium triflates

“…Characteristic NMR data of dicationic iminium salts 5 are given in Table 2. In all cases, only one diastereomer was detected and the magnitude of the 3 J(P,H) coupling constant of the olefinic proton signal suggested a cis-relationship, 10,11,13 i.e. the E-configuration at the olefinic bond.…”

“…The following spectroscopic and analytical instruments were used. NMR: Bruker DRX 400 ( 1d,e, 6 and 1g 13 were prepared by published procedures. could be separated by addition of absolutely dry ether (5 mL) followed by scratching the flask wall with a metal spatula to induce crystallization and filtration under inert atmosphere.…”

“…In the IR spectra, the C=C=C valence vibration appears as a weak absorption in the range 1886-1907 cm -1 . The 13 C NMR signal of the central allenic carbon atom in 2a-e is observed in the δ range 215-233 ppm, corresponding to a low-field shift by about 19-26 ppm relative to the analogous aminoallenes where the + PPh 3 substituent is replaced by a phenyl group. 7,8 Due to the enamine substructure, allenes 2 are readily protonated at the central allenic carbon atom to form the dicationic 3-(triphenylphosphonio)propenyl iminium bis(triflates) 5 (Scheme 2).…”