Ethyl N-(diphenylmethylene)glycinate as anionic glycine equivalent. Monoalkylation, dialkylation and Michael additions under solid-liquid phase-transfer catalysis

5-endo-dig Cyclisations of homopropargylic sulfonamides: a new route to 2,3-dihydropyrroles and β-iodopyrroles

“…), Et 2 NH, 20 °C, ca. 3 h (TLC monitoring); iv, as i, using 1-bromopent-2-yne alkylated 7 with propargyl bromide and the N-protecting group of the resulting propargyl glycine 10 exchanged for a tosyl group. Sonogashira coupling 8 of the sulfonamide 11 so obtained with representative iodides provided excellent yields of the cyclisation substrates 12.…”

Methyl Mercapturate Synthesis: An Efficient, Convenient and Simple Method

“…Using liquid-liquid conditions (entry 1), a complete deesterification of 2 unfortunately resulted. This negative result prompted us on the one hand to suppress water and to use a solid-liquid process [ 46 , 47 , 48 ] and on another hand to replace NaOH by KOH. Three reaction-condition parameters, i.e.…”

An approach to 2,3-dihydropyrroles and β-iodopyrroles based on 5-endo-dig cyclisations

“…were stirred in dry acetonitrile (100 ml) at room temperature. 9 Propargyl bromide (4.70 g, 39.5 mmol, 1.0 equiv.) was then added and the resulting mixture was heated under reflux for 6.5 h. The reaction was then allowed to cool, filtered and concentrated under reduced pressure to give a crude residue which was chromatographed (6 : 1 hexane-ethyl acetate) to give the imine 17 (8.0 g, 70%) as a colourless solid, mp 51-52 ЊC;…”

“…and iodine (0.50 g, 1.94 mmol, 3.0 equiv.). The crude residue was chromatographed (6 : 1 hexane-ethyl acetate) to give the dihydropyrrole 23d (0.20 g, 71%) as a brown oil, ν max /cm Ϫ1 [film] 3500 (w), 2925 (s), 1745 (s), 1598 (w), 1454 (m), 1356 (s), 1215 (m) 1187 (s) and 1090 (m); δ H 1.04-1.09 (3H, m, 5b-CH 3 ), 2.38 (3H, s, Ar-CH 3 ), 2.43-2.63 (4H, m, 1Ј-CH 2 and 3-CH 2 ), 3.73 (3H, s, OCH 3 ), 4.62 (1H, app s, 2-H), 7.30 (2H, d, J = 8.4, 2 × Ar-H) and 7.66 (2H, d, J = 8.4, 2 × Ar-H); δ C 11.7 (2Ј-CH 3 ), 21.7 (Ar-CH 3 ), 23.5 (1Ј-CH 2 ), 41.9 (3-CH 2 ), 52.9 (OCH 3 ), 62.1 (2-CH), 73.9 (4-C), 127.5 (2 × CH), 129.9 (2 × CH), 134.5, 144.5, 146.9 (all C) and 171.2 (C᎐ ᎐ O); m/z [EI] 435 (M ϩ , 2%), 155 (24), 127 (16), 91 (100), 89 (18), 77 (9)…”