Tag: M.W=500-550

Cobo, Angel A. published the artcileCatalytic Asymmetric Synthesis of Cyclopentene-spirooxindoles Bearing Vinylsilanes Capable of Further Transformations, Recommanded Product: (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), the publication is Organic Letters (2019), 21(20), 8196-8200, database is CAplus and MEDLINE.

The authors report a Sc-catalyzed [3 + 2] annulation of alkylideneoxindoles with allenylsilanes for the enantioselective formation of cyclopentene-spirooxindoles containing vinylsilanes. Using a Sc(OTf)₂/PyBOX/BArF complex, the spiroannulation of allenylsilanes affords products with >94:6 dr and >90:10 er. The effect of the counterion and ligand to control selectivity is discussed. The transformation of the vinylsilane is demonstrated using cross-coupling, epoxidation, and Tamao-Fleming oxidation reactions. Competition experiments provide a comparison of nucleophilicity between allyl- and allenylsilanes.

Organic Letters published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C33H29N3O3, Recommanded Product: (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole).

Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem

Zhou, You-Yun published the artcileHighly Enantioselective [3+3] Cycloaddition of Aromatic Azomethine Imines with Cyclopropanes Directed by π-π Stacking Interactions, Related Products of benzoxazole, the publication is Angewandte Chemie, International Edition (2013), 52(5), 1452-1456, database is CAplus and MEDLINE.

A new role of the ligands with sidearm group in a nickel catalyzed [3+3] cycloaddition reaction of isoquinoline azomethineimines with cyclopropanes, in which a prominent π-π stack-directing effect of the sidearm proved to be crucial to the stereochem. control.

Angewandte Chemie, International Edition published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C27H39ClN2, Related Products of benzoxazole.

Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem

Chen, Jiang-Hua published the artcileTris(oxazoline)/copper-catalyzed coupling of alkynes with nitrones: a highly enantioselective access to β-lactams, Application of (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), the publication is Tetrahedron (2012), 68(25), 5042-5045, database is CAplus.

Chiral tris(oxazoline)/Cu(I) complexes are demonstrated as a type of efficient catalysts for the asym. Kinugasa reaction of terminal alkynes with C-arylnitrones, providing a highly enantio- and diastereoselective access to optically active β-lactams. For example, reacting PhCCH with PhN⁺(O^–):CHPh in the presence of CuOTf and tris(oxazoline) I gave β-lactam II as the major isomer.

Tetrahedron published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C33H29N3O3, Application of (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole).

Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem

Wright, Adam J. published the artcilePlanar Chiral Pseudo-Isocoumarins by Copper Catalysed Desymmetrisation, Formula: C33H29N3O3, the publication is European Journal of Inorganic Chemistry (2022), 2022(12), e202100841, database is CAplus.

A new Cu catalyzed desymmetrization reaction of bisalkynyl ferrocenecarboxylic acids using (R,R)-Ph-Pybox results in the 1st asym. synthesis of planar chiral pseudo-isocoumarins in up to 64% enantiomeric excess and up to 99% yield with complete regioselectivity. Tri-functionalized planar chiral ferrocenes were synthesized in five steps from com. available materials, without the need for traditional directing group chem. via an easily diversified route exploiting the double Sonogashira coupling reaction. The absolute configuration of the chiral heterocycles is proven by chem. correlation and CD spectroscopy giving the asym. reaction synthetic utility and opening the way for the rational extension of this method to produce bioactive isocoumarin-fused ferrocene derivatives

European Journal of Inorganic Chemistry published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C6H10O7, Formula: C33H29N3O3.

Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem

Marichev, Kostiantyn O. published the artcileSynthesis of Chiral Tetrasubstituted Azetidines from Donor-Acceptor Azetines via Asymmetric Copper(I)-Catalyzed Imido-Ylide [3+1]-Cycloaddition with Metallo-Enolcarbenes, Related Products of benzoxazole, the publication is Angewandte Chemie, International Edition (2019), 58(45), 16188-16192, database is CAplus and MEDLINE.

The all-cis stereoisomers of tetrasubstituted azetidine-2-carboxylic acids and derivatives that possess three chiral centers have been prepared in high yield and stereocontrol from silyl-protected Z-γ-substituted enoldiazoacetates and imido-sulfur ylides by asym. [3+1]-cycloaddition using chiral sabox copper(I) catalysis [e.g., I + II → III (83%, 90% ee)] followed by Pd/C catalytic hydrogenation (III → IV). Hydrogenation of the chiral p-methoxybenzyl azetine-2-carboxylates occurs with both hydrogen addition to the C=C bond and hydrogenolysis of the ester.

Angewandte Chemie, International Edition published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C33H29N3O3, Related Products of benzoxazole.

Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem

Zhou, You-Yun published the artcileSide-Arm-Promoted Highly Enantioselective Ring-Opening Reactions and Kinetic Resolution of Donor-Acceptor Cyclopropanes with Amines, Category: benzoxazole, the publication is Journal of the American Chemical Society (2012), 134(22), 9066-9069, database is CAplus and MEDLINE.

In the presence of a nonracemic tridentate trisoxazoline ligand I and nickel(II) perchlorate, bis(neopentyl) cyclopropanedicarboxylates II [R = Me₃CCH₂; R¹ = Ph, 4-ClC₆H₄, 4-BrC₆H₄, 3,4-Cl₂C₆H₃, 4-O₂NC₆H₄, 4-MeC₆H₄, 3-MeC₆H₄, 4-MeOC₆H₄, 2-MeOC₆H₄, 3,4-(MeO)₂C₆H₃, 2-thienyl, (E)-PhCH:CH, H₂C:CH, 2-furyl] underwent enantioselective ring-opening reactions with amines R²R³NH [R² = (E)-Me₃CO₂CCH:CHCH₂, PhCH₂, TBDMSOCH₂CH₂, EtO₂CCH₂, H₂C:CHCH₂, (MeO)₂CHCH₂; R³ = PhCH₂, 4-MeOC₆H₄CH₂, Ph; TBDMS = tert-butyldimethylsilyl] to give nonracemic γ-aminodiesters (R)-R¹CH(NR²R³)CH₂CH(CO₂R)₂ [R = Me₃CCH₂; R¹ = Ph, 4-ClC₆H₄, 4-BrC₆H₄, 3,4-Cl₂C₆H₃, 4-O₂NC₆H₄, 4-MeC₆H₄, 3-MeC₆H₄, 4-MeOC₆H₄, 2-MeOC₆H₄, 3,4-(MeO)₂C₆H₃, 2-thienyl, (E)-PhCH:CH, H₂C:CH, 2-furyl; R² = (E)-Me₃CO₂CCH:CHCH₂, PhCH₂, TBDMSOCH₂CH₂, EtO₂CCH₂, H₂C:CHCH₂, (MeO)₂CHCH₂; R³ = PhCH₂, 4-MeOC₆H₄CH₂, Ph] in 59-99% yields and in 80-98% ee. In the presence of I and nickel(II) perchlorate, reaction of II (R = Me₃CCH₂; R¹ = Ph, 4-ClC₆H₄, 4-BrC₆H₄, 4-MeC₆H₄, 3-MeC₆H₄) underwent kinetic resolution with BnNHR² [R² = (E)-Me₃CO₂CCH:CHCH₂, PhCH₂, (MeO)₂CHCH₂] to give nonracemic II in 39-46% yields and in 90-97% ee. The structure of the nickel(II) perchlorate complex with an unsym. analog of I was determined by X-ray crystallog.

Journal of the American Chemical Society published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C17H19N3O7S, Category: benzoxazole.

Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem

Huang, Ke-Xin published the artcileAsymmetric Synthesis of 3-Amine-tetrahydrothiophenes with a Quaternary Stereocenter via Nickel(II)/Trisoxazoline-Catalyzed Sulfa-Michael/Aldol Cascade Reaction: Divergent Access to Chiral Thionucleosides, Category: benzoxazole, the publication is Organic Letters (2021), 23(1), 81-86, database is CAplus and MEDLINE.

A generally useful Ni(II)/trisoxazoline-catalyzed asym. sulfa-Michael/Aldol cascade reaction is introduced to access chiral 3-amine-tetrahydrothiophene derivatives containing a quaternary stereocenter (32 examples, up to 93% yield, > 20:1 dr and 92% ee). Moreover, the novel strategy offers an efficient and convenient approach to construct chiral thionucleoside analogs.

Organic Letters published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C33H29N3O3, Category: benzoxazole.

Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem

Liao, Zhehui published the artcileCopper-Catalyzed Asymmetric Synthesis of Bicyclo[3.n.1]alkenones, Category: benzoxazole, the publication is Journal of Organic Chemistry (2021), 86(7), 5388-5400, database is CAplus and MEDLINE.

A series of highly strained bicyclo[3.n.1]alkenones such as I (R = Me, Et, i-Pr) have been successfully constructed in good to excellent enantioselectivities and moderate to good yields by copper-catalyzed formal [3+3] cycloaddition reaction of 2-oxocycloalkanecarboxylates and aryl vinyl ketones or arylethenyl vinyl ketones via nonracemic oxoalkyl-substituted oxocycloalkanecarboxylates such as II (R = Me, Et, i-Pr). The cycloadducts were selectively converted into various valuable bicyclic ring systems holding considerable potential for the construction of natural and bioactive compounds containing a [3.n.1] moiety.

Journal of Organic Chemistry published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C33H29N3O3, Category: benzoxazole.

Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem