An expedient stereoselective route to the ACE tricyclic core of manzamine A via a palladium-catalysed arylative allene spirocyclisation cascade

Hawkins, Alison; Jakubec, Pavol; Ironmonger, Alan; Dixon, Darren J.

doi:10.1016/j.tetlet.2012.10.111

Cited by 11 publications

(8 citation statements)

References 30 publications

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“…1 H NMR (400 MHz, CDCl 3 ) δ 8.24 (dd, J = 2.4, 0.7 Hz, 1H), 7.55 (dd, J = 9.0, 2.4 Hz, 1H), 6.28 (dd, J = 9.0, 0.7 Hz, 1H), 3.39 -3.30 (m, 4H), 1.66 -1.52 (m, 4H), 0.91 (t, J = 7.4 Hz, 6H). 13 Reaction conditions: Pd(OAc) 2 (10 mol%), 1a (0.1 mmol, 1 eq), 2-iodopyridine (3 eq), base and additive were heated in solvent (1 mL) at 130 o C for 24 h. Yields were determined by GC using undecane as an internal standard. Yields in parentheses were isolated yields.…”

Section: Substrates Synthesismentioning

confidence: 99%

“…Further purification through flash chromatography (n-hexane/Et 2 OAc = 2/1) provided the desired product 9 in 89% yield. Through the known procedure, 13 10 can be produced from 9 in 57% yield.…”

Section: Substrates Synthesismentioning

confidence: 99%

“…(400 MHz, CDCl 3 ) δ 8.54 -8.50 (m, 2H), 8.04 (ddd, J = 7.9, 1.3, 0.8 Hz, 1H), 7.72-7.68 (m, 1H), 7.66 (ddd, J = 8.4, 7.4, 1.3 Hz, 1H), 7.47 (ddd, J = 7.9, 7.4, 1.0 Hz, 1H) , 3.49 (t, J = 7.5 Hz, 2H), 3.21 (t, J = 7.5 Hz, 2H) 13. C NMR (75 MHz, CDCl 3 ) δ 166.7, 143.8, 142.5, 137.7, 132.9, 130.1, 129.5, 124.5, 124.3, 122.0, 116.6, 113.2, 33.1, 27.4.…”

mentioning

confidence: 99%

“…3H), 7.26-7.23 (m, 1H), 7.08 (ddd, J = 7.5, 4.9, 1.2 Hz, 1H), 3.67-3.55 (m, 1H), 3.19 (dd, J = 14.4, 7.8 Hz, 1H), 2.86 (dd, J = 14.4, 6.9 Hz, 1H), 1.42 (d, J = 6.9 Hz, 3H) 13. C NMR (75 MHz, CDCl 3 ) δ 170.7, 164.4, 149.3, 148.0, 138.3, 136.5, 136.1, 134.6, 127.8, 127.3, 122.45, 121.5, 121.4, 121.2, 116.3, 44.4, 38.6, 21.3.…”

mentioning

confidence: 99%

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Synthesis of Alkyl-Substituted Pyridines by Directed Pd(II)-Catalyzed C–H Activation of Alkanoic Amides

Hu¹,

Bach²

2015

Synlett

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Reactions sensitive to air or moisture were carried out under a positive pressure of argon using standard Schlenk techniques. All solvents were reagent grade or better. Dry tetrahydrofuran and dichloromethane were obtained from a MBRAUN MB-SPS 800 solvent purification system. Other dry solvents were obtained from Acros and Sigma-Aldrich and used without further purification. Solvents used for workup and column chromatography were distilled prior to use. Other chemicals were purchased from Sigma-Aldrich, Alfa Aesar, TCI Europe and Acros Organics and were used without further purification. Flash Chromatography was performed on silica gel 60 (Merck, 230-240 mesh). Thin-layer Chromatography (TLC) was performed on Merck silica gel 60 F254 plate. 1 H, 13 C and 19 F NMR spectra were collected using a Bruker AV-400 or a Bruker AV-360 NMR spectrometer. Measurements were done at ambient temperature. 1 H NMR chemical shifts are referenced to the residual hydrogen signals of the deuterated solvent, and the 13 C NMR chemical shifts are referenced to the 13 C signals of the deuterated solvent. 31 F NMR chemical shifts are reported as received. The NMR data are reported in ppm. Abbreviations used in the description of NMR data are as follows: s, singlet; d, doublet; t, triplet; dd = doublet of doublets; dt = doublet of triplets; ddd = doublet of doublet of doublets; m, multiplet; bs, broad singlet. IR spectra were recorded on a a JASCO IR-4100 (ATR) spectrophotometer. Mass spectra were recorded on a Thermo Finnigan LTQ FT (HRMS-ESI) or a Thermo Sientific LTQ Orbitrap XL (HRMS-ESI).

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Section: Substrates Synthesismentioning

confidence: 99%

Section: Substrates Synthesismentioning

confidence: 99%

mentioning

confidence: 99%

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confidence: 99%

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Synthesis of Alkyl-Substituted Pyridines by Directed Pd(II)-Catalyzed C–H Activation of Alkanoic Amides

Hu¹,

Bach²

2015

Synlett

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“…DDQ oxidation, however, provided 4 in a crude yield of 94% and was taken directly to the next step without further purification. 13 We first attempted to convert pyridone 4 into the aryl chloride or bromide, but found that the harsh reaction conditions (refluxing POCl 3 or POBr 3 ) led to low yields of the corresponding product. 14 Instead, formation of triflate 5 proceeded smoothly in 76% yield using trifluoromethanesulfonic anhydride under basic conditions.…”

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confidence: 99%

Efficient synthesis of eudistomin U and evaluation of its cytotoxicity

Roggero

Giulietti

Mulcahy

2014

Bioorganic & Medicinal Chemistry Letters

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Eudistomin U is a member of a subclass of naturally occurring indole alkaloids known as β-carbolines. These molecules are reported to have diverse biological activity and high binding affinity to DNA, which make them attractive targets for total synthesis. We describe an efficient, five-step synthesis of eudistomin U by employing two key reactions: a Bischler-Napieralski cyclization and a Suzuki cross coupling. We also describe the cytotoxicity of eudistomin U against various cancer cell lines and human pathogens, in which we observed potent antibacterial activity against Gram-positive bacteria.

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