Zur bildung metallacyclischer fünfringverbindungen: regioselektivität der addition von alkinen an zirconocenkomplexe

Bis(η5‐cyclopentadienyl)‐1,3‐diphosphabicyclo[1.1.0]butan‐2,4‐diylzirconium: Einfache Synthese eines ungewöhnlichen Moleküls

“…8 So liefert die Hydrolyse erwartungsgemaO Propionsaure 6 (85Y0, nachgewiesen als Methylester; siehe Schema 1).…”

Reductive elimination of α-alkynyl substituted zirconacyclopentenes: formation of cyclobutene derivatives

“…of PMe 3 , a reductive elimination reaction of 2a-c proceeds to afford the complexes 5a-c in 61-86% NMR yields. Treatment of 5a-c with an excess of I 2 produced alkynylcyclobutenes 6a-c in 70-84% NMR yields based on diynes [reaction (2)]. This indicates that reductive elimination of 2a-c took place to give cyclobutene derivatives.…”

Dative Directing Group Effects in Ti-Catalyzed [2+2+1] Pyrrole Synthesis: Chemo- and Regioselective Alkyne Heterocoupling

“…1 H NMR (400 MHz, C 6 D 6 ): δ 7.62−7.60 (m, 2H), 7.35 (t, 3 J HH = 7.8 Hz, 2H), 7.24 (dd, 3 J HH = 7.5 Hz, 4 J HH = 1.7 Hz, 1H), 7.18−7.15 (m, 1H), 6.97−6.93 (m, 2H), 6.90 (td, 3 J HH = 7.9 Hz, 4 J HH = 1.7 Hz, 1H), 6.77−6.71 (m,3H), 6.65−6.58 (m, 3H), 6.54 (tdd, 3 J HH = 7.9, 5.0 Hz, 4 J HH = 1.4 Hz, 1H), 6.39 (d, 3 J HH = 8.0 Hz, 1H), 4.57 (s, 2H, −O−CH 2 − Ar), 2.08 (s, 3H, 2-NC 4 −CH 3 ) ppm. 13 C NMR (101 MHz, C 6 D 6 ): δ 156.0, 150.7 (dd, 1 J CF = 249 Hz, 2 J CF = 12.4 Hz), 148.3 (dd, 1 J CF = 249 Hz, 2 J CF = 13.2 Hz), 138.9, 137.8, 132.3, 131.9, 130.3, 129.8, 128.9, 128.9, 128.6, 127.5 (d, 3 J CF = 10.9 Hz), 126.6, 125.9, 124.4 (dd, 2 J CF = 6.7 Hz, 3 J CF = 4.7 Hz), 124.0 (app t, 2,3 J CF = 3.1 Hz), 123.8 (d, 3 J CF = 1.1 Hz), 121. 5, 120.8, 116.6, 116.4, 113.2, 111.8, 63.6 (dd, 3…”

“…,13 C, 1 H−13 C and 1 H−15 N HMBC, NOESY, and No-D 1 H NMR spectra were collected on Bruker Avance III HD NanoBay 400 MHz, Bruker Avance III HD 500 MHz, or Varian Inova 500 MHz spectrometers. High-resolution mass spectra were collected on Agilent 7200 GC/QTOF-MS, Bruker BioTOF II ESI/TOF-MS, or AB-Sciex 4800 MALDI/ TOF-MS. Chemical shifts are reported with references of residual protio-solvent impurity: 1 H (s, 7.16 ppm for C 6 D 5 H; s, 7.27 for ppm of CHCl 3 ), 13 C (t, 128.39 ppm for C 6 D 6 ; t, 77.23 ppm for CDCl 3 ).…”