287944-06-3Relevant articles and documents
Copper-catalyzed tri- or tetrafunctionalization of alkenylboronic acids to prepare tetrahydrocarbazol-1-ones and indolo[2,3-a]carbazoles
Bi, Hong-Yan,Li, Cheng-Jing,Liang, Cui,Mo, Dong-Liang,Wei, Cui
supporting information, p. 5815 - 5821 (2020/09/21)
We describe a cascade strategy for tri- or tetrafunctionalization of alkenylboronic acids to prepare diverse tetrahydrocarbazol-1-ones and indolo[2,3-a]carbazoles in good yields withN-hydroxybenzotriazin-4-one (HOOBT) and arylhydrazines as oxygen and nitrogen sources, respectively. Mechanistic studies reveal that the domino reaction undergoes the copper-catalyzed Chan-Lam reaction, [2,3]-rearrangement, nucleophilic substitution, oxidation and sequential [3,3]-rearrangement over five steps in a one-pot reaction. The reaction shows a broad substrate scope and tolerates a wide range of functional groups. More importantly, the reaction is easily performed at gram scales and the product is purified by simple extraction, washing, and recrystallization without flash column chromatography. The present protocol features easily available starting materials, high site-marked functionalization, five-step cascade in one pot, multiple C-C/C-O/C-N bond formation, and diversity of indole motifs.
Catalytic enantioselective allyl- and crotylboration of aldehydes using chiral diol·SnCl4 complexes. Optimization, substrate scope and mechanistic investigations
Rauniyar, Vivek,Zhai, Huimin,Hall, Dennis G.
supporting information; experimental part, p. 8481 - 8490 (2009/02/02)
We report a novel class of C2-symmetric chiral diols derived from the hydrobenzoin skeleton. The combination of these diols with SnCl 4 under Yamamoto's concept of Lewis acid assisted Bronsted acidity (LBA catalysis) leads to high levels of asymmetric induction in the allylboration of aldehydes by commercially available allylboronic acid pinacol ester 1a. The corresponding homoallylic alcohol products of synthetically useful aliphatic aldehydes are obtained in excellent yields with up to 98:2 er. This combined acid manifold is also efficient in catalyzing the diastereo- and enantioselective crotylboration of aldehydes, thus providing the propionate units in >95:5 dr and up to 98:2 er. The X-ray crystal structure of the optimal diol·SnCl4 complex, Vivol (4m)·SnCl 4, unambiguously shows the Bronsted acidic character of this LBA catalyst and its highly dissymmetrical environment. Further controls have ruled out a possible boron transesterification mechanism with the chiral diol and point to LBA catalyst-derived activation of the pinacol allylic boronates 1. Due to slow dissociation of the diol·SnCl4 complex, a small excess of diol is required in order to suppress a competing racemic cycle catalyzed by free SnCl4.
1,2-Di(cyclic)substituted benzene compounds
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Page/Page column 68, (2008/06/13)
In one aspect, the present invention provides compounds having formula (1) or (100), a salt thereof or a hydrate of the foregoing, which compounds exhibit excellent cell adhesion inhibitory action or cell infiltration inhibitory action, and are useful as therapeutic or prophylactic agents for various inflammatory diseases and autoimmune diseases associated with adhesion and infiltration of leukocytes, such as inflammatory bowel disease (particularly ulcerative colitis or Crohn's disease), irritable bowel syndrome; rheumatoid arthritis, psoriasis, multiple sclerosis, asthma and atopic dermatitis. wherein R10 represents optionally substituted cycloalkyl, etc., R20-23 represent hydrogen, alkyl, alkoxy, etc., R30-32 represent hydrogen, alkyl, oxo, etc., and R40 represents optionally substituted alkyl, etc.
