193966-77-7Relevant articles and documents
Biomimetic deiodination of thyroid hormones and iodothyronamines-a structure-activity relationship study
Mondal, Santanu,Mugesh, Govindasamy
supporting information, p. 9490 - 9500 (2016/10/22)
Mammalian selenoenzymes, iodothyronine deiodinases (DIOs), catalyze the tyrosyl and phenolic ring deiodination of thyroid hormones (THs) and play an important role in maintaining the TH concentration throughout the body. These enzymes also accept the decarboxylated thyroid hormone metabolites, iodothyronamines (TAMs), as substrates for deiodination. Naphthalene-based selenium and/or sulphur-containing small molecules have been shown to mediate the regioselective tyrosyl ring deiodination of thyroid hormones and their metabolites. Herein, we report on the structure-activity relationship studies of a series of peri-substituted selenium-containing naphthalene derivatives for the deiodination of thyroid hormones and iodothyronamines. Single crystal X-ray crystallographic and 77Se NMR spectroscopic studies indicated that the intramolecular Se?X (X = N, O and S) interactions play an important role in the deiodinase activity of the synthetic mimics. Furthermore, the decarboxylated metabolites, TAMs, have been observed to undergo slower tyrosyl ring deiodination than THs by naphthyl-based selenium and/or sulphur-containing synthetic deiodinase mimics and this has been explained on the basis of the strength of Se?I halogen bonding formed by THs and TAMs.
New strategy for the synthesis of proaporphine and homoproaporphine-type alkaloids from a common intermediate
Magnus, Philip,Marks, Kyle D.,Meis, Alan
, p. 3872 - 3877 (2015/06/02)
Starting with 3-bromo-4,5-dimethoxybenzaldehyde 14, it was coupled with the boronic anhydride 15 using standard Suzuki reaction conditions to give 16 (91%). The aldehyde 16 was exposed to classical nitro-aldol reaction conditions to give 17 (88%), and conjugatively reduced with DIBAL-H to give 18 (91%). Protection of the amine 18 as its N-carbamate derivative 19, followed by condensation with glycol aldehyde dimer under acidic reaction conditions gave 20 (78%). Subsequent conversion of 20 into its mesylate derivative 21, and exposure to CsF under aprotic reaction conditions gave 22 (81%). Deprotection of 22 gave (±)-stepharine 10 in 29% overall yield though 8 steps. A similar sequence of reaction conditions converted the amine 18 into the -NTs protected homoproaporphine adduct 28.
Boronic acid catalysis as a mild and versatile strategy for direct carbo- and heterocyclizations of free allylic alcohols
Zheng, Hongchao,Ghanbari, Sina,Nakamura, Shinji,Hall, Dennis G.
supporting information; experimental part, p. 6187 - 6190 (2012/08/13)
BAC to the future: Boronic acid catalysis (BAC) was applied to the direct activation of alcohols leading to the preparation of carbocycles (see scheme), benzofurans, tetrahydrofurans, pyrrolidines, pyrans, piperidines, and various polycyclic compounds. The reactions proceed under mild conditions that circumvent the use of reactive leaving groups like halides. Copyright
