116485-96-2Relevant articles and documents
Catalytic Asymmetric Cross-Dehydrogenative Coupling of 2H-Chromenes and Aldehydes
Pan, Xinhui,Liu, Xigong,Sun, Shutao,Meng, Zhilin,Liu, Lei
, p. 1187 - 1190 (2018)
The first catalytic asymmetric cross-dehydrogenative coupling of 2H-chromenes with aldehydes using o-chloranil (3,4,5,6-tetrachloro-1,2- benzoquinone) as an oxidant has been described. The organocatalytic process is tolerated with a broad range of structurally and electronically varied 2H-chromenes and aldehydes with good yield and high enantiocontrol.
Ruthenium complexes of phosphine-amide based ligands as efficient catalysts for transfer hydrogenation reactions
Yadav, Samanta,Vijayan, Paranthaman,Yadav, Sunil,Gupta, Rajeev
, p. 3269 - 3279 (2021/03/16)
This work presents three mononuclear Ru(ii) complexes of tridentate phosphine-carboxamide based ligands providing a NNP coordination environment. The octahedral Ru(ii) ion shows additional coordination with co-ligands; CO, Cl and CH3OH. All three Ru(ii) complexes were thoroughly characterized including their crystal structures. These Ru(ii) complexes were utilized as catalysts for the transfer hydrogenation of assorted carbonyl compounds, including some challenging biologically relevant substrates, using isopropanol as the hydrogen source. The binding studies illustrated the coordination of the isopropoxide ion by replacing a Ru-ligated chloride ion followed by the generation of the Ru-H intermediate that was isolated and characterized and was found to be involved in the catalysis.
A Bioinspired Cascade Sequence Enables Facile Assembly of Methanodibenzo[b,f][1,5]dioxocin Flavonoid Scaffold
Liu, Hongxin,Wang, Yu,Guo, Xueying,Huo, Luqiong,Xu, Zhifang,Zhang, Weimin,Qiu, Shengxiang,Yang, Bao,Tan, Haibo
, p. 546 - 549 (2018/02/10)
A remarkable bioinspired EDDA-mediated method for the selective construction of biologically interesting and highly strained bridged methanodibenzo[b,f][1,5]dioxocin flavonoid scaffold was uncovered by starting from a variety of readily available acylphloroglucinol and 2-hydroxycinnamaldehyde substrates. This method merges a fascinating olefin isomerization/hemiacetallization/dehydration/[3 + 3]-type cycloaddition cascade reaction driven by an in situ generated chromenylium intermediate and provides a convenient and viable synthetic strategy for the efficient access of such flavonoid analogues.
Formal Carbene Insertion into C?O or C?N Bond: An Efficient Strategy for the Synthesis of 2-Substituted 2H-Chromene Derivatives from Chromene Acetals or Hemiaminal Ethers
Zhang, Dan,Hu, Wenhao
supporting information, p. 2446 - 2452 (2018/05/14)
We report the palladium/Br?nsted acid co-catalyzed formal insertion of carbene into the C?O or C?N bond of 2H-chromene acetals or hemiaminal ethers. This transformation was initiated by the Br?nsted acid-promoted cleavage of the C?O or C?N bond, followed by modification of the leaving alcohol or amino fragments with palladium carbenes, and reassembly of the modified fragments. A variety of C-2 functionalized 2H-chromene derivatives were obtained in moderate yield (43～75%) with good to excellent diastereoselectivities (up to >95:5 dr) under mild conditions. (Figure presented.).
Trimethylsilyl iodide mediated one-pot synthesis of 2-allyl-2H-chromenes
Padhi, Birakishore,Reddy, D. Srinivas,Mohapatra, Debendra K.
, p. 542 - 547 (2015/01/30)
A new and efficient metal-free trimethylsilyl iodide (TMSI) catalyzed one-pot synthesis of 2-allyl-2H-chromenes has been developed that takes place under mild conditions. The synthesis proceeds through a Wittig reaction by using (triphenylphosphoranylidene)acetaldehyde to form an ohydroxycinnamaldehyde derivative followed by a tandem isomerization and C-O and C-C bond-forming reactions. The procedure was carried out at room temperature in the presence of 20 mol-% of TMSI and allyltrimethylsilane in tetrahydrofuran (THF) and provided the 2-allyl-2H-chromenes in good to excellent yields.
Enantioselective copper-catalyzed alkynylation of benzopyranyl oxocarbenium ions
Srinivas, Harathi D.,Maity, Prantik,Yap, Glenn P. A.,Watson, Mary P.
, p. 4003 - 4016 (2015/09/07)
We have developed highly enantioselective, copper-catalyzed alkynylations of benzopyranyl acetals. By using a copper(I) catalyst equipped with a chiral bis(oxazoline) ligand, high yields and enantioselectivities are achieved in the alkynylation of widely
Enantioselective addition of boronates to chromene acetals catalyzed by a chiral bronsted acid/lewis acid system
Moquist, Philip N.,Kodama, Tomohiro,Schaus, Scott E.
supporting information; experimental part, p. 7096 - 7100 (2010/11/04)
Chiral α ,β-dihydroxy carboxylic acids catalyze the enantioselective addition of alkenyl and aryl boronates to chromene acetals. The optimal carboxylic acid is the easily available tartaric acid amide shown in the scheme. Spectroscopic and kinetic mechanistic studies demonstrate that an exchange process generates a reactive dioxoborolane intermediate leading to enantioselective addition to the pyrylium ion formed from the chromene acetal.
Chemical and enzyme-catalysed syntheses of enantiopure epoxide and diol derivatives of chromene, 2,2-dimethylchromene, and 7-methoxy-2,2-dimethylchromene (precocene-1)
Boyd, Derek R.,Sharma, Narain D.,Boyle, Rosemary,Evans, Timothy A.,Malone, John F.,McCombe, Kenneth M.,Dalton, Howard,Chima, Jagdeep
, p. 1757 - 1765 (2007/10/03)
Procaryotic (bacterial) dioxygenase-catalysed asymmetric dihydroxylation of chromene and 2,2-dimethylchromene to yield the (4S)-enantiomers of the corresponding cis-diols exclusively is reported. The epoxide, and derived cis- and trans-diol products from the previously reported eucaryotic (mammalian) metabolism of precocene-1 (7-methoxy-2,2-dimethylchromene), and the corresponding epoxide and diol derivatives of chromene and 2,2-dimethylchromene, have now been obtained in enantiopure form by chemical resolution of the corresponding bromohydrins using methoxy-(trifluoromethyl)phenylacetic acid (MTPA) or camphanate esters. The absolute configurations of the epoxides, cis- and trans-diols have been determined by chemical synthesis from, and stereochemical correlation with, the corresponding camphanate and MTPA esters. X-Ray crystal structure analysis has provided an unequivocal method for assignment of the absolute stereochemistry in each case.
Chiral Chromenes: Synthesis, Separation of Enantiomers and Barriers to Racemization
Loncar, Linda,Otocan, Klaudio,Mintas, Mladen,Troetsch, Thomas,Mannschreck
, p. 209 - 216 (2007/10/02)
2H-Chomenes 3 and 4 have been synthesized by reduction of the appropriate lactone with diisobutylaluminium hydride and subsequent O-alkylation of the resulting lactols.Separations or enrichments of enantiomers were achieved by liquid chromatography on tri
Biotransformation of Unsaturated Heterocyclic Rings by Pseudomonas putida to Yield cis-Diols
Boyd, D. R.,Sharma, N. D.,Boyle, R.,McMurray, B. T.,Evans, T. A.,et al.
, p. 49 - 51 (2007/10/02)
New cis-diols metabolites of both aromatic and non-aromatic heterocyclic rings have been isolated from growing cultures of a mutant strain of the soil bacterium Pseudomonas putida (UV4) and stereochemically assigned; a novel heterocyclic cis-diol of benzothiophene, 2,3-dihydroxy-2,3-dihydrobenzothiophene is found to exist exclusively in the cis-configuration in water but equilibrates readily with the trans-isomer.
