104654-69-5Relevant academic research and scientific papers
PhI(OAc)2-mediated alkoxyoxygenation of β,γ-unsaturated ketoximes: Preparation of isoxazolines bearing two contiguous tetrasubstituted carbons
Ye, Chenghao,Kou, Xuezhen,Yang, Guoqiang,Shen, Jiefeng,Zhang, Wanbin
supporting information, p. 1148 - 1152 (2019/03/26)
A PhI(OAc)2-promoted dioxygenation of allyl oximes, including one alkoxylation, has been developed. This reaction can give isoxazoline products bearing two contiguous tetrasubstituted carbons. Various oximes substrates bearing different aryl groups and tetrasubstituted-olefin moieties were compatible with the mild reaction conditions. A two-electron oxidation pathway was proposed based on results of preliminary mechanistic studies.
Asymmetric Aza-Wacker-Type Cyclization of N-Ts Hydrazine-Tethered Tetrasubstituted Olefins: Synthesis of Pyrazolines Bearing One Quaternary or Two Vicinal Stereocenters
Kou, Xuezhen,Shao, Qihang,Ye, Chenghao,Yang, Guoqiang,Zhang, Wanbin
supporting information, p. 7587 - 7597 (2018/06/04)
We have developed an asymmetric aza-Wacker-type cyclization of N-Ts hydrazine-tethered tetrasubstituted olefins, affording optically active pyrazolines bearing chiral tetrasubstituted carbon stereocenters. This reaction is tolerant to a broad range of substrates under mild reaction conditions, giving the desired chiral products with high enantioselectivities. Generation of two vicinal stereocenters on the C=C double bonds was also achieved with high selectivities, a process which has been rarely studied for Wacker-type reactions. A mechanistic study revealed that this aza-Wacker-type cyclization undergoes a syn-aminopalladation process. It was also found that for substrates bearing two linear alkyl substituents on the outer carbon atom of the olefin, both of which are larger than a methyl group, the alkyl substituent that is cis to the intranucleophilic group participates more readily in β-hydride elimination. When one of the two alkyl substituents on the outer carbon atom of the olefin is a methyl group, β-hydride elimination proceeds selectively at the methylene side, thus both diastereomers can be prepared via switching the configuration of the olefin. Furthermore, the product can be converted to a pharmaceutical compound in high yields over three steps.
Iron-Catalyzed Cross-Coupling of Alkenyl Acetates
G?rtner, Dominik,Stein, André Luiz,Grupe, Sabine,Arp, Johannes,Von Wangelin, Axel Jacobi
supporting information, p. 10545 - 10549 (2015/09/02)
Stable C-O linkages are generally unreactive in cross-coupling reactions which mostly employ more electrophilic halides or activated esters (triflates, tosylates). Acetates are cheap and easily accessible electrophiles but have not been used in cross-couplings because the strong C-O bond and high propensity to engage in unwanted acetylation and deprotonation. Reported herein is a selective iron-catalyzed cross-coupling of diverse alkenyl acetates, and it operates under mild reaction conditions (0 C, 2 h) with a ligand-free catalyst (1-2 mol%). Iron clad: Acetates are underutilized electrophiles in metal-catalyzed cross-coupling reactions because of the strong alkenyl C-O bond and their propensity to engage in unwanted reactions. Combination of a ligand-free low-valent Fe catalyst with nucleophilic organomagnesium reagents, low temperature, and short reaction times results in highly selective cross-couplings with alkenyl acetates.
Diastereospecific nazarov cyclization of fully substituted dienones: Generation of vicinal all-carbon-atom quaternary stereocenters
Jolit, Anais,Vazquez-Rodriguez, Saleta,Yap, Glenn P. A.,Tius, Marcus A.
supporting information, p. 11102 - 11105 (2013/10/22)
No vacancy: Fully substituted dienones that are highly polarized by a vinylogous carbonate group were found to undergo a remarkably rapid and diastereospecific Nazarov cyclization that led to cyclopentenones with vicinal all-carbon-atom quaternary centers (see example; SEM=2-(trimethylsilyl) ethoxymethyl, Tf=trifluoromethanesulfonyl). Copyright
(2-hydroxy)ethyl-thioureas useful as modulators of alpha2B adrenergic receptors
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, (2008/06/13)
Compounds of formula (i) and of formula (ii) wherein the symbols have the meaning disclosed in the specification, specifically or selectively modulate α2B and/or α2C adrenergic receptors in preference over α2A adrenergic receptors, and as such are useful for alleviating chronic pain and allodynia and have no or only minimal cardivascular and/or sedatory activity.
EFFICIENT SYNTHESIS OF SOME 2-OXASPIRONONA-1-ONES AS ANISATIN MODELS
Kato, Michiharu,Kitahara, Haruo,Yoshikoshi, Akira
, p. 1785 - 1788 (2007/10/02)
As a model study for the synthesis of anisatin, 2-oxaspirononane and 5-hydroxy-5-methyl-2-oxaspirononane were synthesized from methyl cyclohexanecarboxylate and 2-ethoxycarbonylcyclohexanone, respectively, and these oxenates were submitted to ru
