- Umpolung Strategy for Arene C?H Etherification Leading to Functionalized Chromanes Enabled by I(III) N-Ligated Hypervalent Iodine Reagents
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The direct formation of aryl C?O bonds via the intramolecular dehydrogenative coupling of a C?H bond and a pendant alcohol represents a powerful synthetic transformation. Herein, we report a method for intramolecular arene C?H etherification via an umpoled alcohol cyclization mediated by an I(III) N-HVI reagent. This approach provides access to functionalized chromane scaffolds from primary, secondary and tertiary alcohols via a cascade cyclization-iodonium salt formation, the latter providing a versatile functional handle for downstream derivatization. Computational studies support initial formation of an umpoled O-intermediate via I(III) ligand exchange, followed by competitive direct and spirocyclization/1,2-shift pathways. (Figure presented.).
- Mikhael, Myriam,Guo, Wentao,Tantillo, Dean J.,Wengryniuk, Sarah E.
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supporting information
p. 4867 - 4875
(2021/09/14)
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- Ni-Catalyzed Cross-Electrophile Coupling of Aryl Triflates with Thiocarbonates via C-O/C-O Bond Cleavage
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A nickel-catalyzed reductive coupling of aryl triflates with thiocarbonates is reported here. Both electron-rich and -deficient aryl C(sp2)-O electrophiles as well as a class of O-tBu S-alkyl thiocarbonates are compatible with the optimized reaction conditions, as evidenced by 49 examples. The reaction also proceeds with good chemoselective cleavage of the C-O bond with regard to thioesters. This work broadens the scope of nickel-catalyzed reductive cross-electrophile coupling reactions.
- Zhu, Zhaodong,Gong, Yuxin,Tong, Weiqi,Xue, Weichao,Gong, Hegui
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supporting information
p. 2158 - 2163
(2021/04/05)
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- Introduction of Aryl Fluorosulfates into the Realm of Catellani Reaction Substrates
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Application of activated phenol fluorosulfates as substrates in a Pd/NBE mediated sequential alkylation-arylation, commonly known as a Catellani reaction, is presented. These substrates provide a level of complementarity to the commonly used aryl halides and, in combination with a plethora of existing Catellani reaction variations, enable even wider application of this powerful synthetic tool.
- Bieliū Nas, Vidmantas,De Borggraeve, Wim M.
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p. 15706 - 15717
(2019/11/21)
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- Directed ortho Metalation (D o M)-Linked Corriu-Kumada, Negishi, and Suzuki-Miyaura Cross-Coupling Protocols: A Comparative Study
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A systematic study of the widely used, titled name reaction transition-metal-catalyzed cross-coupling reactions with attention to context with the directed ortho metalation (D o M) is reported. In general, the Suzuki-Miyaura and Negishi protocols show gre
- Quesnelle, Claude A.,Snieckus, Victor
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supporting information
p. 4395 - 4412
(2018/11/21)
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- A synthetic camptothecin compound in 5-6 method of and ring structure (by machine translation)
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The present invention discloses a synthetic camptothecin compound in the 5 [...] 6 method of and ring structure, the method is that the conjugated structure of formula II occurs in the solvent alkene alkyne ester series cyclization reaction in the molecule, thus the system results in the type shown in I of the 5 [...] 6 and ring structure, the specific equation is: In the formula: R 1 and R 2 are respectively and independently selected from hydrogen, alkyl, cycloalkyl, aryl or heterocyclic group; or, R 1 and R 2 together form a saturated or unsaturated carbocyclic or heterocyclic; R 3 and R 4 are respectively and independently selected from hydrogen, alkyl, cycloalkyl, aryl or heterocyclic group; or, R 3 and R 4 together form a saturated or unsaturated carbocyclic or heterocyclic rings; selected from R C 1-C 4 alkyl; P is amino protecting group. The stated method of this invention has the advantages of simple operation, safety and environmental protection, low production cost, high yield, is suitable for large-scale production, and the like, to promote such compounds in the medical field with the extensive application of an important value. (by machine translation)
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Paragraph 0044; 0045
(2016/10/20)
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- Method for synthesizing 6-6 fused ring structure in berberine and ebony natural product
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The invention discloses a method for synthesizing a 6-6 fused ring structure in berberine and ebony natural products. The method comprises the step of carrying out intramolecular tandem cyclization reaction on conjugated enyne ester with a structure shown in a formula II in a solvent, so that the 6-6 fused ring structure shown in a formula I is obtained, a specific reaction formula is described in the specification, wherein R1 and R2 are respectively independently selected from hydrogen, alkyl, naphthenic base, aryl and heterocyclic radical; or R1 and R2 form a saturated or unsaturated carboatomic ring or heterocyclic ring together; R3 and R4 are respectively independently selected from hydrogen, alkyl, naphthenic base, aryl and heterocyclic radical; or R3 and R4 form a saturated or unsaturated carboatomic ring or heterocyclic ring together; R is selected from C1-C4 alkyl; P is an amino-protecting group. The method disclosed by the invention has the advantages of simple operation, safety, environmental friendliness, low production cost, high yield and adaptability to large scale production and has important value in promotion of extensive use of the compound in the filed of medicines.
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Paragraph 0038; 0039
(2016/11/17)
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- Intermolecular mizoroki-heck reaction of aliphatic olefins with high selectivity for substitution at the internal position
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New ligand for old reaction: The title reaction of aryltriflates with aliphatic olefins leads to substitution at the internal position with high selectivity. The ratio of the desired isomer (shown in the scheme) to the sum of all other isomers is generall
- Qin, Liena,Ren, Xinfeng,Lu, Yunpeng,Li, Yongxin,Zhou, Jianrong
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supporting information; experimental part
p. 5915 - 5919
(2012/07/30)
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- Investigation of self-immolative linkers in the design of hydrogen peroxide activated metalloprotein inhibitors
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A series of self-immolative boronic ester protected methyl salicylates and metal-binding groups with various linking strategies have been investigated for their use in the design of matrix metalloproteinase proinhibitors.
- Jourden, Jody L. Major,Daniel, Kevin B.,Cohen, Seth M.
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supporting information; experimental part
p. 7968 - 7970
(2011/08/07)
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- STIMULUS-TRIGGERED PRODRUGS
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Set forth herein, inter alia, are compositions and methods for treating diseases with prodrugs. Provided herein are prodrug compositions for inhibiting the function of proteins, compositions and methods for treating diseases associated with oxidative compounds, oxidatively-sensitive prodrugs of inhibitors of metalloproteases. and methods of inhibiting metalloproteases using oxidatively-sensitive prodrugs.
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Page/Page column 40
(2012/01/13)
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- Muscarinic Receptor Antagonists
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Provided are muscarinic receptor antagonists, which can be useful in treating various diseases of the respiratory, urinary or gastrointestinal system mediated through muscarinic receptors. Also provided are processes for preparing compounds described herein, pharmaceutical compositions comprising compounds described herein, and methods for treating diseases mediated through muscarinic receptors.
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Page/Page column 17
(2009/01/23)
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- New hybrid ligands with a trans-1,2-diaminocyclohexane backbone: Competing chelation modes in palladium-catalyzed enantioselective allylic alkylation
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Three new hybrid ligands with trans-1,2-diaminocyclohexane backbone have been synthesized from (1R,2R)-2-aminocyclohexylcarbamic acid tert-butyl ester (4), which is prepared through an indirect monoprotection of the diamine. The ligands are (1R,2R)-N-{2-[2-(dimethylamino)benzoyl]amino}-cyclohexyl-2-(diphenylphospha nyl)benzamide and its di-n-butylamino- and diphenylamino-derivatives (3a-c), which belong to formal P,N-type chelates with possible wide bite angles in the metal chelation. To evaluate the new hybrid ligands against well-known P,N- and P,P-chelates (1 and 2), they were employed in the palladium-catalyzed allylic alkylations between two standard racemic allylic acetates, 2-acetoxy-1,3-diphenyl-2-propene (14a) and 2-acetoxy-1,3-dimethyl-2-propene (14b), and dimethyl malonate under different reaction conditions. The catalytic system with the new ligands showed good reactivity toward both the substrates with moderate enantioselectivities (up to 78% ee toward 14a and 80% ee toward 14b). Of particular note, dramatic changes in the sense and in the degree of the enantioselectivity were observed depending on the ligands and reaction conditions, which suggested a different chelation mode was competing with the supposed P,N-chelation mode. An X-ray crystal structure of a chelated palladium complex [Pd(3c)(η3-PhCHCH-CHPh)]PF6 was obtained, which showed a P,O-chelation mode in which a carboxamide oxygen acted as the O-ligand. This is the first example of the enantioselective palladium-catalyzed allylic alkylation in which a P,O-chelated complex of a carboxamide group participated as the ligand group.
- Kim, Young Kook,Lee, Seok Jong,Ahn, Kyo Han
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p. 7807 - 7813
(2007/10/03)
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- AMP deaminase inhibitors. 3. SAR of 3-(carboxyarylalkyl)coformycin aglycon analogues
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N3-Substituted coformycin aglycon analogues with improved AMP deaminase (AMPDA) inhibitory potency are described. Replacement of the 5-carboxypentyl substituent in the lead AMPDA inhibitor 3-(5-carboxypentyl)-3,6,7,8- tetrahydroimidazo[4,5-d][1,3]diazepin-8-ol (2) described in the previous article with various carboxyarylalkyl groups resulted in compounds with 10- 100-fold improved AMPDA inhibitory potencies. The optimal N3 substituent had m-carboxyphenyl with a two-carbon alkyl tether. For example, 3-[2-(3-carboxy- 5-ethylphenyl)ethyl]-3,6,7,8-tetrahydroimidazo[4,5-d][1,3]diazepin-8-ol (43g) inhibited human AMPDA with a K(i) = 0.06 μM. The compounds within the series also exhibited > 1000-fold specificity for AMPDA relative to adenosine deaminase.
- Kasibhatla, Srinivas Rao,Bookser, Brett C.,Probst, Gary,Appleman, James R.,Erion, Mark D.
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p. 1508 - 1518
(2007/10/03)
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