36773-67-8Relevant academic research and scientific papers
C-O-bond cleavage of esters with a naphthyl group in the higher triplet excited state during two-color two-laser flash photolysis
Cai, Xichen,Sakamoto, Masanori,Yamaji, Minoru,Fujitsuka, Mamoru,Majima, Tetsuro
, p. 3143 - 3149 (2007)
A C-O-bond cleavage of esters having a naphthyl group, NpCO-OR and RCO-ONp (Np = α- and βnaphthyl (αNp and βNp, respectively), R = Ph and Me), was found during the two-color two-laser flash photolysis in acetonitrile. The C-O-bond cleavage occurred when NpCO-OR and RCO-ONp were excited to the singlet excited states (S1). On the other hand, no reaction occurred from the lowest triplet excited states (T 1). When NpCO-OR(T1) and RCO-ONp(T1) were excited to the higher triplet excited states (Tn) using the second laser during the two-color two-laser flash photolysis, the C-O-bond cleavage occurred. The C-O-bond cleavage quantum yield (Φ) was estimated from the plots of the T1state esters disappeared within a laser flash versus the second laser intensities. The C-O-bond cleavage in βNpCO- OPh(Tn) occurred more efficiently than in αNpCO- OPh(Tn) and that in PhCO-OβNp(Tn) occurred more efficiently than in PhCO-OαNp(Tn). The Φ value for ester with Ph and β-Np groups was larger than that for ester with Ph and α-Np groups. The Φ value for MeCO-OαNp(T n) was similar to those for PhCO-ONp(Tn), while that for MeCO-OβNp(Tn) was much smaller than those for PhCO-ONp(T n) and MeCO-OαNp(Tn). On the other hand, no C-O-bond cleavage was observed in NpCO-OMe(Tn). The Φ value depended on the characters of the groups (Np, Ph, and Me) on the ester. Whether R is Ph or Me with or without π electron, respectively, is important for the C-O-bond cleavage. In other words, electronic delocalization of the T n state including Np and ester groups is necessary for the occurrence of the C-O-bond cleavage in NpCO-OR(Tn) and RCO-ONp(Tn).
Palladium Catalyzed Regioselective Cyclization of Arylcarboxylic Acids via Radical Intermediates with Diaryliodonium Salts
An, Guoqiang,Wang, Limin,Han, Jianwei
, p. 8688 - 8693 (2021/11/24)
Palladium-catalyzed C2-arylation/intramolecular acylation with arylcarboxylic acids was developed by using diaryliodonium salts. The protocol has the advantage of good step-economy by two chemical bonds formation in one pot.
Fluoride anion-initiated bis-trifluoromethylation of phenyl aromatic carboxylates with (trifluoromethyl)trimethylsilane
Takahashi, Kenjiro,Ano, Yusuke,Chatani, Naoto
supporting information, p. 11661 - 11664 (2020/10/19)
The fluoride anion-initiated reaction of phenyl aromatic carboxylates with (trifluoromethyl)trimethylsilane (Me3SiCF3) that results in the formation of O-silyl-protected 2-aryl-1,1,1,3,3,3-hexafluoroisopropanols is reported. A phenoxide anion, generated during the trifluoromethylation of the phenyl carboxylate, also activates the Me3SiCF3, which permits a catalytic amount of the fluoride anion source to be used. Various functional groups, which can be used for further elaboration, are tolerated in the reaction.
Transesterification of (hetero)aryl esters with phenols by an Earth-abundant metal catalyst
Chen, Jianxia,Namila,Bai, Chaolumen,Baiyin, Menghe,Agula, Bao,Bao, Yong-Sheng
, p. 25168 - 25176 (2018/07/29)
Readily available and inexpensive Earth-abundant alkali metal species are used as efficient catalysts for the transesterification of aryl or heteroaryl esters with phenols which is a challenging and underdeveloped transformation. The simple conditions and the use of heterogeneous alkali metal catalyst make this protocol very environmentally friendly and practical. This reaction fills in the missing part in transesterification reaction of phenols and provides an efficient approach to aryl esters, which are widely used in the synthetic and pharmaceutical industry.
Decarbonylative Methylation of Aromatic Esters by a Nickel Catalyst
Okita, Toshimasa,Muto, Kei,Yamaguchi, Junichiro
, p. 3132 - 3135 (2018/05/28)
A Ni-catalyzed decarbonylative methylation of aromatic esters was achieved using methylaluminums as methylating agents. Dimethylaluminum chlorides uniquely worked as the methyl source. Because of the Lewis acidity of aluminum reagents, less reactive alkyl esters could also undergo the present methylation. By controlling the Lewis acidity of aluminum reagents, a chemoselective decarbonylative cross-coupling between alkyl esters and phenyl esters was successful.
Method of coupling, and the coupling method using the aromatic group-substituted heterocyclic compound
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Paragraph 0202-0207, (2020/09/17)
Provided is an easy method (coupling method) capable of easily synthesizing a compound group in which aromatic molecules and aromatic molecules are coupled, a compound group in which aromatic molecules and alkene molecules are coupled, and the like without producing halogen waste and without the need to use scarce and expensive palladium. A compound (A) shown by general formula (A): Ar-H and a compound (B1) shown by general formula (B1): RaOCO-Ar', a compound (B2) shown by general formula (B2): RbCH=C(Ar")2, or a compound (B3) shown by general formula (B3): RcOCOCH=C(Ar")2 are reacted in the presence of a nickel compound.
Mechanistic Insight into Weak Base-Catalyzed Generation of Carbon Monoxide from Phenyl Formate and Its Application to Catalytic Carbonylation at Room Temperature without Use of External Carbon Monoxide Gas
Konishi, Hideyuki,Matsubara, Mika,Mori, Keisuke,Tokiwa, Takaki,Arulmozhiraja, Sundaram,Yamamoto, Yuta,Ishikawa, Yoshinobu,Hashimoto, Hiroshi,Shigeta, Yasuteru,Tokiwa, Hiroaki,Manabe, Kei
supporting information, p. 3592 - 3601 (2017/10/24)
The mechanisms of the weak base-catalyzed generation of carbon monoxide (CO) and phenol from phenyl formate were investigated by experimental and theoretical methods. Kinetic studies revealed a first-order reaction in both phenyl formate and the base. The reaction was found to proceed by an E2 α-elimination pathway, which involves the abstraction of the formyl proton of phenyl formate, simultaneously generating CO and phenoxide. The reaction rate was affected by the substituents on phenyl formate, the polarity of solvents, and the basicity of bases. The mechanistic insight obtained from these studies permitted the chemical control of the rate of CO generation, which was the key to the development of the external CO-free Pd-catalyzed phenoxycarbonylation of haloarenes at room temperature. Because of the mild reaction conditions and wide substrate scope, this phenoxycarbonylation constitutes a general, safe, and practical method to synthesize arenecarboxylic acid esters. (Figure presented.).
Pd/C catalyzed phenoxycarbonylation using: N -formylsaccharin as a CO surrogate in propylene carbonate, a sustainable solvent
Gautam, Prashant,Kathe, Prasad,Bhanage, Bhalchandra M.
supporting information, p. 823 - 830 (2017/08/15)
This work reports the first Pd/C catalyzed phenoxycarbonylation of aryl iodides using N-formylsaccharin as a CO surrogate. Advantageously, the reaction could be carried out in propylene carbonate, an environmentally benign and sustainable polar aprotic solvent under CO surrogacy. Using N-formylsaccharin as a CO surrogate allows the usage of cheaper and readily available phenols as the coupling partner. A range of phenyl esters could be synthesized under mild, co-catalyst free, ligand free and additive free conditions, including multi-substituted novel phenyl esters. The Pd/C catalyst could be recycled up to four times with only a slight loss in activity. The reaction could be scaled up to gram scale synthesis.
Highly Active Manganese-Mediated Acylation of Alcohols with Acid Chlorides or Anhydrides
Joo, Seong-Ryu,Youn, Young-Jin,Hwang, Young-Ran,Kim, Seung-Hoi
, p. 2665 - 2669 (2017/10/07)
To explore further the practical uses of highly active manganese (Mn?), a variety of alcohols were treated with Mn?, and the resulting complexes were coupled with acid chlorides and/or acetic anhydride in the absence of any extra catalyst. The subsequent reactions took place smoothly under mild conditions, providing the corresponding O-acylation products in good to excellent isolated yields.
Immobilized palladium metal-containing ionic liquid-catalyzed alkoxycarbonylation, phenoxycarbonylation, and aminocarbonylation reactions
Khedkar, Mayur V.,Sasaki, Takehiko,Bhanage, Bhalchandra M.
, p. 287 - 293 (2013/08/25)
Immobilized palladium metal-containing ionic liquid (ImmPd-IL), a structurally well-defined transition metal complex, is explored as an immobilized, phosphine-free catalyst for carbonylation reactions, including alkoxycarbonylation, phenoxycarbonylation, and aminocarbonylation reactions. The effect of various reaction parameters, such as solvent, base, time, temperature, and CO pressure on carbonylation reactions using ImmPd-IL catalyst was investigated. The optimized protocol was applied to a wide variety of substituted aryl iodides and various alcohol/phenols and amines having different steric and electronic properties and afforded the corresponding products in good to excellent yield. The developed catalytic system circumvents the use of phosphine ligands, with an additional advantage of palladium catalyst recovery and reuse for up to four consecutive cycles. The recycled catalyst was characterized using XPS analysis.
