24249-82-9Relevant academic research and scientific papers
Bis-Pocket Porphyrins without meso-Substituents: Tetramethyltetra(2,4,6-triisopropylphenyl)porphyrin I and Tetrametyltetraterphenylporphyrin I
Bag, Nilkamal,Chern, Shuenn-Shing,Peng, Shie-Ming,Chang, C. K.
, p. 6409 - 6412 (1995)
A facile synthesis of meso-unsubstituted but doubly fenced porphyrins is described.The required pyrroles are made by the Barton-Zard method from 2,4,6-triisopropylbenzaldehyde and 2,6-diphenylbenzaldehyde.An X-ray structure confirms the type I pattern.
METHOD FOR PRODUCING CARBONYL COMPOUND
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Paragraph 0032-0035; 0037-0040, (2018/03/23)
PROBLEM TO BE SOLVED: To provide a method for producing a carbonyl compound, allowing for improvement of ease of production and furthermore allowing for reduction of production cost, by positively utilizing inexpensive iodine. SOLUTION: A carbonyl compound is produced by mixing primary alcohol or secondary alcohol, and iodic acid (HIO3) in a non-solvent or an aprotic polar solvent based on the following general formula (1), where R1 is an optionally substituted linear- or branched 1-12C aliphatic group, or an optionally substituted aromatic group; R2 is a hydrogen atom, an optionally substituted linear- or branched 1-12C alkyl group, or an optionally substituted aromatic group; R1 and R2 each may be coupled with each other to form a ring of aromatic group or a non-aromatic group. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
Click-binol-phosphoric acid catalysts in intramolecular enantioselective oxidative C[sbnd]H-bond functionalization
Stockerl, Sebastian,Gutiérrez, Daniel,García Manche?o, Olga
, p. 572 - 585 (2016/12/16)
Counteranion-catalysis represents an appealing but challenging approach for the development of enantioselective oxidative C[sbnd]H bond functionalization reactions. In this work, a new family of 3,3′-triazolyl BINOL-derived phosphoric acids was synthesized and employed in the intramolecular asymmetric C[sbnd]H bond functionalization of N-aryl substituted tetrahydroisoquinolines. As previously reported with related structures, the presence of the triazole groups on the catalysts was key to attain enantioselectivity. Our study also shows the importance of choosing the appropriate regioisomeric triazole groups at the BINOL backbone to achieve a more efficient chirality transfer. Moderate enantiomeric ratios were obtained with the N-benzamide substrates, whereas the change of the nature of the nucleophile fragment was translated to a dramatic loss of the enantioselectivity. Therefore, it can be foreseen that there is a need for designing further superior catalyst structures to develop future counter-anion organocatalyzed asymmetric C[sbnd]H bond functionalization reactions.
Synthetic utility of iodic acid in the oxidation of benzylic alcohols to aromatic aldehydes and ketones
Imai, Sho,Togo, Hideo
, p. 6948 - 6954 (2016/10/13)
Various primary and secondary benzylic alcohols were efficiently oxidized to aromatic aldehydes and aromatic ketones with iodic acid in DMF at 60?°C for 2?h and with iodic acid in the presence of TEMPO (5?mol?%) in DMF at room temperature, respectively. The former method was effective for the oxidation of sterically hindered alcohols at 60?°C and the latter method was effective for the oxidation of less sterically hindered alcohols at room temperature.
Iminoborylene complexes: evaluation of synthetic routes towards BN-allenylidenes and unexpected reactivity towards carbodiimides
Niemeyer,Kelly,Riddlestone,Vidovic,Aldridge
supporting information, p. 11294 - 11305 (2015/06/25)
The synthetic and reaction chemistries of cationic iminoborylene complexes [LnM=B=N=CR2]+, which feature a unique heterocumulene structure, have been systematically investigated. Precursors of the type CpFe(CO)2B(Cl)NCAr2 (Ar = p-Tol/Mes, 5c/d) have been generated by B-centred substitution chemistry using CpFe(CO)2BCl2 and suitable lithiated ketimines - a reaction which is found to be highly sensitive to the steric bulk at both the metal fragment and the ketimino group. Carbonyl/phosphine exchange (using PCy3 or PPh3), followed by halide abstraction allows for the generation of the cationic iminoborylenes [CpFe(PR3)(CO)(BNCAr2)]+[BArX 4]- (R = Cy, Ar = p-Tol/Mes, 12c/d; R = Ph, Ar = Mes, 13d; ArX = 3,5-X2C6H3 where X = Cl, CF3) which have been characterized spectroscopically and by X-ray crystallography. The reactivity of these iminoborylene systems towards a range of nucleophiles and unsaturated substrates has been investigated. The latter includes the first examples of M=B metathesis reactivity with a carbodiimide, and results in Fe=B cleavage and formation of the isonitrile complexes [CpFe(PCy3)(CO)(CNR)]+[BArCl 4]- (R = iPr/Cy, 16/17).
A direct and mild formylation method for substituted benzenes utilizing dichloromethyl methyl ether-silver trifluoromethanesulfonate
Ohsawa, Kosuke,Yoshida, Masahito,Doi, Takayuki
, p. 3438 - 3444 (2013/06/26)
A silver trifluoromethanesulfonate (AgOTf)-promoted direct and mild formylation of benzenes has been developed. The reaction utilizing dichloromethyl methyl ether (Cl2CHOMe) and AgOTf powerfully formylated various substituted benzenes under temperature conditions as low as -78 C without losing the protecting groups on the phenolic hydroxyl group.
Substrate range of the titanium TADDOLate catalyzed asymmetric fluorination of activated carbonyl compounds
Bertogg, Andreas,Hintermann, Lukas,Huber, Dominique P.,Perseghini, Mauro,Sanna, Maria,Togni, Antonio
body text, p. 353 - 403 (2012/05/07)
The substrate range of the [TiCl2(TADDOLate)] (TADDOL=α,α,α′,α′-tetraaryl-1,3-dioxolane-4, 5-dimethanol)-catalyzed asymmetric α-fluorination of activated β-carbonyl compounds has been investigated. Optimal conditions for catalysis are characterized by using 5 mol-% of TiCl2(naphthalen-1- yl)-TADDOLate) as catalyst in a saturated (0.14 mol/l) MeCN solution of F-TEDA (1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis- [tetrafluoroborate]) at room temperature. A series of α-methylated β-keto esters (3-oxobutanoates, 3-oxopentanoates) with bulky benzyl ester groups (60-90% ee) or phenyl ester (67-88% ee) have been fluorinated readily, whereas α-acyl lactones were also readily fluorinated, but gave lower inductions (13-46% ee). Double stereochemical differentiation in β-keto esters with chiral ester groups raised the stereoselectivity to a diastereomeric ratio (dr) of up to 96.5:3.5. For the first time, β-keto S-thioesters were asymmetrically fluorinated (62-91.5% ee) and chlorinated (83% ee). Lower inductions were observed in fluorinations of 1,3-diketones (up to 40% ee) and β-keto amides (up to 59% ee). General strategies for preparing activated β-carbonyl compounds as important model substrates for asymmetric catalytic α-functionalizations are presented (>60 examples). Copyright
Synthesis and reactivity of an unprecedented osmium(VIII) alkylidene
Martin, Véronique,Blakey, Simon
scheme or table, p. 6800 - 6803 (2009/04/06)
The synthesis of a family of Os(VIII) alkylidene complexes, the highest oxidation state alkylidenes known to date, and their reactivity toward small organic molecules are reported.
Correlated rotations in benzylfluorene derivatives: Structure, conformation, and stereodynamics
Casarini, Daniele,Lunazzi, Lodovico,Mazzanti, Andrea
, p. 2811 - 2818 (2008/09/19)
(Graph Presented) Fluorene derivatives, having substituted benzyl groups bonded to position 9, have been investigated by variable temperature NMR spectroscopy. Stereodynamic processes involving restricted rotation about the fluorenyl-CH2 and ar
Generation and detection of a relatively persistent carboxylic acid enol-2,2-bis(2′,4′,6′-triisopropylphenyl)ethene-1,1-diol
Frey, Joseph,Rappoport, Zvi
, p. 5169 - 5181 (2007/10/03)
Ditipyl ketene (tipyl = 2,4,6-triisopropylphenyl) (20), ditipylacetic acid (19), and 2,2-ditipyl bis-(trimethylsilyl) acetal 28 were prepared as potential precursors for the enol of 19, i.e., 2,2-ditipylethene-l,l-diol (25). Protonation of the dianion of
