Regioselective Ylide Formation on Acetal-Functionalized Trialkyl Phosphonium Salts: Extending the Scope of Carbonyl Homologation

Abstract

The discovery of a complex-induced proximity effect and scope of regioselective ylide formation on acetal- and ketal-functionalized trialkylphosphine-derived phosphonium salts is explored as a route to homologated unsaturated carbonyl derivatives.

Sulfamyl Radicals Direct Photoredox-Mediated Giese Reactions at Unactivated C(3)–H Bonds

“…1,1,1-trifluoro-2-methylpropan-2-aminium chloride, 1 (2-phenylpropan-2-yl) azide, 2 (2-phenylpropan-2-yl) amine, 3 [Ir(dF(CF3)ppy)2(bpy)](PF6) (5b) , 4 [Ir(dF(CF3)ppy)2(dtbbpy)](PF6) (5a) , 5 4-CzIPN (5e) , 6 [Ir(dF(CF3)ppy)2(5,5'-dCF3bpy)](PF6) (5c) , 7 [Ir(dF(CF3)ppy)2(4,4'-dCF3bpy)](PF6) (5d) , 7 4,4'bis(trifluoromethyl)-2,2'-bipyridine, 8 5,5'-bis(trifluoromethyl)-2,2'-bipyridine, 9 tetrakis(triphenylphosphine)palladium(0) , 10 (3R,4S)-3-chloro-4-methylhexanoic acid, 11 4-cyclopentylbutanal, 12 (2-(1,3-dioxolan-2-yl)ethyl)triphenylphosphonium bromide, 13 6methylhept-5-en-2-yn-1-ol, 14 6-methylheptan-1-ol, 15 dehydroabietinol, 16 (S)-3methylpentan-1-ol, 17 3-cyclopentylpropan-1-ol, 18 ((5,5dimethylhexyl)oxy)trimethylsilane, 19 2,2,2-trifluoro-N-(4-methylpentyl)acetamide (S11), 20 4-methoxy-N-(4-methylpentyl)benzamide (S13), 7 (methyl 6-((N-(tertbutyl)sulfamoyl)oxy)hexanoate (1c), 21 3-phenylpropyl tert-butylsulfamate (13j) , 22 methyl 2-phenyl acrylate, 23 phenyl acrylate, 24 dimethylfumarate, 25 phenyl vinyl ketone, 26 N-methylacrylamide, 27 and but-3-yn-1-yl acrylate 28 (benzyl (S)-2-(tert-butyl)-4methylene-5-oxooxazolidine-3-carboxylate), 29 were prepared by literature methods.…”

“…NMR Spectrometry NMR spectra were obtained on Varian iNOVA spectrometers operating at 400 or 500 MHz for 1 H NMR, 126 MHz for 13 C NMR, and 376 MHZ for 19 F NMR, and are reported as chemical shifts (δ) in parts per million (ppm). Spectra were referenced internally according to residual solvent signals ( 1 H: CDCl3, 7.26 ppm; C6D6, 7.16 ppm; CD3CN, 1.94 ppm; 13 C: CDCl3, 77.0 ppm, C6D6, 128.06 ppm; CD3CN: 118.3 ppm).…”

“…NMR Spectrometry NMR spectra were obtained on Varian iNOVA spectrometers operating at 400 or 500 MHz for 1 H NMR, 126 MHz for 13 C NMR, and 376 MHZ for 19 F NMR, and are reported as chemical shifts (δ) in parts per million (ppm). Spectra were referenced internally according to residual solvent signals ( 1 H: CDCl3, 7.26 ppm; C6D6, 7.16 ppm; CD3CN, 1.94 ppm; 13 C: CDCl3, 77.0 ppm, C6D6, 128.06 ppm; CD3CN: 118.3 ppm). Data for NMR spectra use the following abbreviations to describe multiplicity: s, singlet; br s, broad singlet; d, doublet; t, triplet; dd, doublet of doublets; td, triplet of doublets; tt, triplet of triplets; ddd, doublet of doublet of doublets; ddt, doublet of doublet of triplets; app dd, apparent doublet of doublets; m, multiplet.…”

“…1 H NMR (700 MHz, CDCl3) δ 4.72 (dd, J = 9.1, 6.1 Hz, 1H), 3.75 (d, J = 10.9 Hz, 1H), 3.39 (d, J = 10.8 Hz, 1H), 2.06 (s, 3H), 1.80-1.76 (m, 4H), 1.68-1.63 (m, 1H), 1.59-1.49 (m, 7H), 1.40-1.32 (m, 4H), 1.24-1.16 (m, 3H), 1.06-1.03 (m, 2H), 0.95 (s, 3H), 0.90 (s, 3H), 0.85 (s, 3H) 13 C NMR (176 MHz, CD3CN) δ 171.4, 81.7, 65.5, 56.9, 56.5, 55.0, 42. All novel triethylammonium sulfamate salts were prepared using a previously described method.…”

“…The product was obtained as an off-white oil (9.4 g, 98% yield) following removal of solvent under reduced pressure. 1 H NMR (400 MHz, CDCl3) δ 10.38 (br s, 1H), 3.58 (m, 1H), 3.15 (m, 6H), 1.37 (t, J = 7.3, 9H), 1.20 (d, J = 6.5 Hz, 6H) 13 C NMR (126 MHz, CDCl3) δ 46.2, 45.9, 23.9, 8.7 IR (neat) n 3446 (br), 2968 (w), 2705 (w), 1635 (w), 1472 (w), 1398 (w), 1381 (w), 1363 (m), 1159 (s), 1029 (s), 982 (m), 865 (w), 838 (w), 729 (m), 620 (m), 552 (m) cm -1 HRMS (ESI) m/z: [M -HN + Et3] -Calcd for C3H9NO3S -138.0230; Found 138.0229…”