1530-27-4Relevant academic research and scientific papers
Alkenylation of unactivated alkyl bromides through visible light photocatalysis
Zhou, Quan-Quan,Düsel, Simon Josef Siegfried,Lu, Liang-Qiu,K?nig, Burkhard,Xiao, Wen-Jing
supporting information, p. 107 - 110 (2019/01/03)
Two visible-light driven alkenylation reactions of unactivated alkyl bromides, which were enabled by the use of Ir(dF(CF3)ppy)2(dtbbpy)PF6 as the photocatalyst and (TMS)3SiH as the atom transfer reagent to activate the alkyl bromides, were described for the first time. These protocols can be used to produce a variety of alkenes from easily available feedstock with good reaction efficiency and high chemoselectivity under mild reaction conditions. To further demonstrate the applicability of the present strategy, the alkenylation of bioactive molecules and glycosyl bromides, as well as the alkynylation of unactivated alkyl bromides, was proven to be feasible.
Triazole-functionalized N-heterocyclic carbene complexes of palladium and platinum and efficient aqueous Suzuki-Miyaura coupling reaction
Gu, Shaojin,Xu, Hui,Zhang, Na,Chen, Wanzhi
experimental part, p. 1677 - 1686 (2011/08/05)
Imidazolium salts bearing triazole groups are synthesized via a copper catalyzed click reaction, and the silver, palladium, and platinum complexes of their N-heterocyclic carbenes are studied. [Ag4(L1) 4](PF6)4, [Pd(L1)Cl](PF6), [Pt(L1)Cl](PF6) (L1=3-((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)-1- (pyrimidin-2-yl)-1H-imidazolylidene), [Pd2(L2)2Cl 2](PF6)2, and [Pd(L2)2](PF 6)2 (L2=1-butyl-3-((1-(pyridin-2-yl)-1H-1,2,3-triazol-4- yl)methyl) imidazolylidene) have been synthesized and fully characterized by NMR, elemental analysis, and X-ray crystallography. The silver complex [Ag 4(L1)4](PF6)4 consists of a Ag 4 zigzag chain. The complexes [Pd(L1)Cl](PF6) and [Pt(L1)Cl](PF6), containing a nonsymmetrical NCN' pincer ligand, are square planar with a chloride trans to the carbene donor. [Pd 2(L2)2Cl2](PF6)2 consists of two palladium centers with CN2Cl coordination mode, whereas the palladium in [Pd(L2)2](PF6)2 is surrounded by two carbene and two triazole groups with two uncoordinated pyridines. The palladium compounds are highly active for Suzuki-Miyaura cross coupling reactions of aryl bromides and 1,1-dibromo-1-alkenes in neat water under an air atmosphere.
Behavior of biradicals generated from a Norrish type-I reaction of 2,2- diphenylcycloalkanones. Chain-length dependence and magnetic field effects
Suzuki, Itsuko,Tanaka, Ryoko,Yamaguchi, Akinori,Maki, Shin-Ichiro,Misawa, Hiroaki,Tokumaru, Katsumi,Nakagaki, Ryoichi,Sakuragi, Hirochika
, p. 103 - 113 (2007/10/03)
The reaction course of acyl-diphenylmethyl biradicals (α-oxo-ω, ω- diphenyl-α,ω-alkanediyl biradicals), O=C↑(CH2)η-2-C↑Ph2 (3BR-η), generated from the Norrish type-I reaction of 2,2-diphenylcycloalkanones (CK- η) with various ring sizes in methanol, is switched from intramolecular disproportionation (n = 6, 7), giving a diphenylalkenal, to acylphenyl recombination (n ≥ 9), affording a cyclophane derivative. The behavior of 3BR-9 derived from CK-9 was studied in detail; the photolysis of CK-9 afforded an open-chain and a cyclic decarbonylation product together with an unsaturated aldehyde and a 4-methylene-2,5-cyclohexadienyl ketone (a pre- cyclophane). The photolysis of this ketone gave the same products that arose from the photolysis of CK-9, presenting the possibility that the decarbonylation products and a part of the aldehyde are formed as secondary products during irradiation. The magnetic field dependence of the lifetimes of 3BR-η (η = 12 and 13) generated from CK-12 and 13, respectively, was measured in methanol by means of a pulsed-laser excitation technique. The rate constants for intersystem crossing showed a maximum at a relatively low field strength, which decreased with increasing the field strength to level off to an asymptotic value at > 1.5 kG. The results show that the role of hyperfine coupling in intersystem crossing is less important in these systems, presumably because of the presence of a carbonyl oxygen and the absence of a hydrogen atom at the radical center.
Effects of chain length on behavior of biradicals generated from Norrish type I reaction of 2,2-diphenylcycloalkanones. Isolation and photochemistry of intermediate methylenecyclohexadienyl ketones
Tanaka,Suzuki,Yamaguchi,Misawa,Sakuragi,Tokumaru
, p. 3651 - 3654 (2007/10/02)
The reaction course of biradicals, O=C(↑)-(CH2)(n-2)-C(↑)Ph2, generated from Norrish type I reaction of 2,2-diphenylcycloalkanones with various ring sizes, is switched from intramolecular disproportionation (n = 6,7) to acyl-phenyl r
Reaction of α-Silyl Esters with Grignard Reagents: A Synthesis of β-Keto Silanes and Ketones. Preparation of the Douglas Fir Tussock Moth Pheromone
Larson, Gerald L.,Hernandez, David,Lopez-Cepero, Ingrid Montes de,Torres, Luz E.
, p. 5260 - 5267 (2007/10/02)
A variety of α-diphenylmethylsilyl esters have been prepared and reacted with Grignard reagents.The reaction is relatively slow in refluxing THF and can be controlled to allow the addition of 1 equiv of the Grignard reagent, providing the corresponding β-keto silane.Protiodesilylation of the β-keto silane results in the overall conversion of an ester to a ketone.This ester to ketone methodology has been applied to a two-step synthesis of the pheromone of the Douglas fir tussock moth.The β-keto silanes are viable precursors to regioselectively generated enol silyl ethers.The reaction of ethyl 2-methyl-2-(diphenylmethylsilyl)propionate with vinylmagnesium bromide or 2-methyl 1-propenylmagnesium bromide results in the addition of 2 equiv of the Grignard reagent, the second in a Michael fashion.
