ChemInform Abstract: Synthesis of (S)-(+)-2-tert-Butyl-2-methyl-1,3-benzodioxole-4-carboxylic Acid: A New Type Chiral Derivation Reagent for Amines and Alcohols.

ChemInform ◽  
1990 ◽  
Vol 21 (19) ◽  
Author(s):  
Y. NISHIDA ◽  
H. OHRUI ◽  
H. MEGURO
Keyword(s):  
Synlett ◽  
2020 ◽  
Vol 32 (01) ◽  
pp. 45-50
Author(s):  
Udo Nubbemeyer ◽  
Analuisa Nava ◽  
Lukas Trippe ◽  
Andrea Frank ◽  
Lars Andernach ◽  
...  

AbstractStarting from methyl cycloheptatrienyl-1-carboxylate, 6-acylation was successfully achieved employing glutaryl chloride in the presence of AlCl3 under controlled reaction conditions to furnish keto carboxylic acid product. After protection of this keto carboxylic acid as tert-butyl ester, reagent-controlled enantioselective reductions delivered configuration-defined methyl-6-hydroxylalkyl cycloheptatriene-1-carboxylates with up to 80% ee. Whereas simple NaBH4 reduction of the keto carboxylic acid and subsequent lactonization afforded a methyl-6-tetrahydropyranonyl cycloheptatriene-1-carboxylate. Resolution using chiral HPLC delivered the product enantiomers with up to >99% ee Finally, ECD analyses enabled structure elucidation. The products are used as key intermediates in enantioselective 6,11-methylene-lipoxin B4 syntheses.


2014 ◽  
Vol 229 (2) ◽  
pp. 127-128 ◽  
Author(s):  
Chuanhong Zhang ◽  
Jianguo Lin ◽  
Gaochao Lv ◽  
Yang Cao ◽  
Shineng Luo

Abstract C22H23N3O4, triclinic, P1¯ (no. 2), a = 6.992(3) Å, b = 8.159(4) Å, c = 18.778(8) Å, α = 92.118(7)°, β = 93.463(7)°, γ = 101.623(7)°, V = 1045.9 Å3, Z = 2, Rgt(F) = 0.0576, wRref(F2) = 0.1778, T = 296 K.


2006 ◽  
Vol 36 (21) ◽  
pp. 3117-3123 ◽  
Author(s):  
Alexandra Fritsche ◽  
Heidrun Deguara ◽  
Matthias Lehr

1997 ◽  
Vol 75 (12) ◽  
pp. 1830-1843 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Jörg Metge ◽  
Steven J. Rettig ◽  
James Trotter

The syntheses of a number of aromatic aldonitrones of N-(2-hydroxyphenylmethyl)hydroxylamine and their subsequent reactions with diphenylborinic or carboxylic acid derivatives are reported. Crystals of 8-(4-dimethylaminophenylmethylene)-6,6-diphenyl-5,7-dioxa-8-azonia-6-borata-5H-6,7,8,9-tetrahydrobenzocycloheptene, 2b, are triclinic, a = 10.6802(8), b = 11.1809(4), c =10.1520(3) Å, α = 105.847(3)°, β = 92.567(4)°, γ = 84.610(5)°, Z = 2, space group PĪ, and those of C-(4-dimethylaminophenyl)-N-(2-hydroxyphenylmethyl)nitrone, 6e, are monoclinic, a = 12.2319(8), b = 7.071(1), c = 17.2005(9) Å, β = 107.520(4)°, Z = 4, space group P21/a. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R = 0.035 and 0.032 (Rw = 0.036 and 0.032) for 3379 and 1800 reflections with I ≥ 3σ(I), respectively. Compound 2b is representative of a new type of heterocyclic B,N-betaine. The solid state structure of 6e (the precursor to 2b) shows that only small topological changes, but significant changes in the electron distribution, occur upon the formation of the diphenylboron chelate. Keywords: aromatic aldonitrones, organoboron compounds, crystal structures.


2021 ◽  
Author(s):  
Kevser Harmandar ◽  
Kevin Granados-Tavera ◽  
Merve Keskin ◽  
Mehmet Nebioğlu ◽  
İlkay Şişman ◽  
...  

An asymmetric zinc phthalocyanine dye (KH1) bearing three 2,6-di-tert-butyl-4-methylphenoxy donor groups and carboxylic acid anchoring group was synthesized as a sensitizer for dye-sensitized solar cells (DSSCs). The DSSC based on...


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