Synthesis of the Bestmann-Ohira Reagent

Pietruszka, Jörg; Witt, Andreas

doi:10.1055/s-2006-950307

Cited by 105 publications

(77 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Commercial reagents (Sigma Aldrich or Alfa Aesar) were used as received with the exception of palladium(II) acetate (Sigma Aldrich) and XPhos (Sigma Aldrich), which were stored in a nitrogen-filled govebox. The Ohira-Bestmann reagent 2 and carbomethoxy methylene triphenyl phosphorane (Ph 3 P=CHCO 2 Me) 3 were prepared according to known procedures.…”

Section: Methodsmentioning

confidence: 99%

Catalytic Anti-Markovnikov Transformations of Hindered Terminal Alkenes Enabled by Aldehyde-Selective Wacker-Type Oxidation

Kim

Grubbs

et al. 2016

J. Am. Chem. Soc.

View full text Add to dashboard Cite

A new strategy for the functionalization of sterically hindered terminal olefins is reported. Alkenes bearing quaternary carbons at the allylic or homoallylic position are readily oxidized to the corresponding aldehydes by palladium/copper/nitrite catalysis. A broad range of functional groups including esters, nitriles, silyl ethers, vinylogous esters, ketones, lactones, and β-ketoesters are tolerated under the reaction conditions. The crude aldehyde products can be transformed further, enabling direct conversion of hindered terminal alkenes to various other synthetically useful functional groups, resulting in formal anti-Markovnikov hydroamination, among other transformations.

show abstract

Section: Methodsmentioning

confidence: 99%

Catalytic Anti-Markovnikov Transformations of Hindered Terminal Alkenes Enabled by Aldehyde-Selective Wacker-Type Oxidation

Kim

Grubbs

et al. 2016

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…The reaction mixture was filtered through a pad of celite and the filtrate concentrated in vacuo. The residue was puri- E N N U N G (CH 3 ) 3 )), 32.6 (C19), 34.7 (C25), 37.6 (C18), 38.1 (C16), 38 …”

Section: Methodsmentioning

confidence: 99%

“…After separation of the layers, the aqueous layer was extracted with CH 2 Cl 2 . The combined organic extracts were washed with 1m HCl, saturated NaHCO 3 and saturated NaCl solution, dried over MgSO 4 Alkyne 46: Diethyl-1-diazo-2-oxopropylphosphonate [38] (45) (124 mg, 0.52 mmol, 2 equiv) was added to a solution of aldehyde 45, which was obtained in the previous step (188 mg, 0.26 mmol), and K 2 CO 3 (122 mg, 0.88 mmol, 3.4 equiv) in MeOH (5 mL) followed by stirring of the mixture for 12 h at room temperature. The reaction mixture was diluted with Et 2 O (50 mL) and washed with an aqueous solution (5 %) of NaHCO 3 (20 mL).…”

Section: A C H T U N G T R Ementioning

confidence: 99%

See 1 more Smart Citation

Synthesis and Biological Evaluation of Cruentaren A Analogues

Vintonyak

Calà

Lay

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

The complex macrolide cruentaren A is a highly selective and potent inhibitor of F-ATPase (F-type adenosine triphosphatase). As it shows some resemblance to benzolactone enamides like apicularen A, it was of interest to perform some structure-activity studies to delineate the key functional groups that are responsible for the activity. Building upon our previously developed route to cruentaren A, which is based on a ring-closing alkyne metathesis reaction (RCAM), several cruentaren analogues were prepared. Replacement of the 3-hydroxy hexanoic part with acids that lack the hydroxy group function resulted in a significant drop in cytotoxicity and F-ATPase inhibition. Furthermore, two enamide analogues 23 and 50 were synthesized. However, these compounds were only cytotoxic in the micromolar range. Under the conditions for cleavage of the C3 aromatic methyl ether, the enamide function was transformed to the corresponding oxazinanone, resulting in analogues 25 and 52.

show abstract

“…42 Treatment of chloroacetone with KI followed by reaction with trimethyl phosphite furnishes 22. Deprotonation of 22 using sodium hydride followed by treatment with 4-acetamidobenzene sulfonyl azide 26 produces the Ohira-Bestmann reagent.…”

Section: Preparation Of Phosphonate Reagent 23mentioning

confidence: 99%