- Palladium-Catalyzed C(sp3)?H Arylation of Primary Amines Using a Catalytic Alkyl Acetal to Form a Transient Directing Group
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C?H Functionalization of amines is a prominent challenge due to the strong complexation of amines to transition metal catalysts, and therefore typically requires derivatization at nitrogen with a directing group. Transient directing groups (TDGs) permit C?H functionalization in a single operation, without needing these additional steps for directing group installation and removal. Here we report a palladium catalyzed γ-C?H arylation of amines using catalytic amounts of alkyl acetals as transient activators (e.g. commercially available (2,2-dimethoxyethoxy)benzene). This simple additive enables arylation of amines with a wide range of aryl iodides. Key structural features of the novel TDG are examined, demonstrating an important role for the masked carbonyl and ether functionalities. Detailed kinetic (RPKA) and mechanistic investigations determine the order in all reagents, and identify cyclopalladation as the turnover limiting step. Finally, the discovery of an unprecedented off-cycle free-amine directed ?-cyclopalladation of the arylation product is reported.
- St John-Campbell, Sahra,Ou, Alex K.,Bull, James A.
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supporting information
p. 17838 - 17843
(2018/11/23)
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- Novel Compounds For The Treatment Of GI Disorders 682
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The present invention relates to novel imidazole compounds having a positive allosteric GABAB receptor (CUR) modulator effect, methods for the preparation of said compounds and to their use, optionally in combination with a GABAB agonist, for the inhibition of transient lower esophageal sphincter relaxations, for the treatment of gastroesophageal reflux disease, as well as for the treatment of functional gastrointestinal disorders and irritable bowel syndrome (IBS).
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Page/Page column 10
(2008/12/04)
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- Sulfamates as antiglaucoma agents
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Sulfamate esters of the formula where A is aryloxyalkyl, p is the number of unreacted hydroxy groups present on the alkyl moiety and may be zero, z is the number of --OS(O)2 NR1 R2 groups attached to carbons of the alkyl moiety and is always at least one; R1 and R2 are selected from hydrogen, loweralkyl, carboxy, and the like are useful in treating glaucoma.
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- Compounds having one or more aminosulfaonyloxy radicals useful as pharmaceuticals
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Methods of treating chronic arthritis and osteoporosis which utilize both known and novel compounds which would fall under the general formula:(HO)p--A--[--OS(O) 2 NR 1 R 2 ] zwherein A encompasses a wide range of values including but not limited to aryl, loweralkyl, cycloalkyl, and carbohydrates including sucrose and fructose; p is equal to the number of unreacted hydroxy groups contained on the molecule and may be zero; z is the number of --OS(O) 2 NR 1 R 2 groups and is always at least one; R 1 and R 2 are selected from hydrogen, loweralkyl, carboxy and the like; a novel process for preparing the compounds is provided wherein an appropriate sulfamic acid aryl ester is reacted with a hydroxy substituted A radical which may or may not contain thereon protected carboxyl, amino or hydroxy substituents, in an aprotic solvent containing a tertiary amine base. Pharmaceutical compositions for the treatment of chronic arthritis and osteoporosis are also provided.
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