36317-60-9Relevant articles and documents
Selective Cross-Dehydrogenative C(sp3)-H Arylation with Arenes
Hao, Hong-Yan,Mao, Yang-Jie,Xu, Zhen-Yuan,Lou, Shao-Jie,Xu, Dan-Qian
supporting information, p. 2396 - 2402 (2020/03/13)
Selective C(sp3)-C(sp2) bond construction is of central interest in chemical synthesis. Despite the success of classic cross-coupling reactions, the cross-dehydrogenative coupling between inert C(sp3)-H and C(sp2)-H bonds represents an attractive alternative toward new C(sp3)-C(sp2) bonds. Herein, we establish a selective inter-and intramolecular C(sp3)-H arylation of alcohols with nondirected arenes that thereby provides a general pathway to access a wide range of β-arylated alcohols, including tetrahydronaphthalen-2-ols and benzopyran-3-ols, with high to excellent chemo-and regioselectivity.
The remarkable solvent effect on Zn(OAc)2-Catalyzed Hydrosilylation of ketones
Ozasa, Hiroki,Kondo, Kazuhiro,Aoyama, Toyohiko
experimental part, p. 989 - 990 (2010/09/17)
The combination of Zn(OAc)2 and N,N-dimethylformamide was found to effectively hydrosilylate various ketones at room temperature. Furthermore, our protocol allows the chemoselective reduction of a formyl group in the presence of a ketone group.
Cross-coupling reaction between alcohols through sp3 C-H activation catalyzed by a ruthenium/lewis acid system
Zhang, Shu-Yu,Tu, Yong-Qiang,Fan, Chun-An,Jiang, Yi-Jun,Shi, Lei,Cao, Ke,Zhang, En
supporting information; experimental part, p. 10201 - 10205 (2009/10/15)
A study was conducted to investigate the Ru-catalyzed/acid mediated C-C cross-coupling reaction between alcohols. It was observed during the experiment that functionalized alcohols can be synthesized by sp3 C-H bond activation of primary alcohols. The study also investigated the stereoselectivity of this coupling reaction with tertiary alcohols. The study used 1,1-diphenylethanol and ethanol as substrate and transition metal catalysts with various acid and solvents. The study also found that the RhCl(PPh 3)3 and RuCpCl(PPh3)2 catalysts accelerate the catalyze of the reactions with a lower yield. The study also observed that the ruthenium-catalyzed Lewis acid can enhance the cross-coupling reaction between ethanol and the alkene 1,1-diphenylethene. Lewis acid can promote the C-H bond activation and removal of hydroxy in the reaction.
Asymmetric transesterification of secondary alcohols catalyzed by feruloyl esterase from Humicola insolens
Hatzakis, Nikos S.,Smonou, Ioulia
, p. 325 - 337 (2007/10/03)
A new asymmetric transesterification of secondary alcohols catalyzed by feruloyl esterase from Humicola insolens has been found. Although alcohols are not the natural substrates for this enzyme, a high R enantioselectivity was observed. Stereochemical studies showed that variations in substrate structure lead to strong variations in enantioselectivity. The highest enantioselectivities are obtained when the β-carbon of the secondary alcohol is tertiary or quaternary.
Triisobutylaluminium promoted reductive rearrangement of substituted vinyl ethers to homologous alcohols
Du Roizel,Sollogoub,Pearce,Sinay
, p. 1507 - 1508 (2007/10/03)
Substituted vinyl ethers carrying electron-donating groups in the ether moiety undergo smooth oxygen to carbon rearrangement with triisobutylaluminium to afford chain extended alcohols.
Reinvestigation of the Chemistry of Arylcarbenes in Polycrystalline Alcohols at 77 K. Secondary Photochemistry of Matrix-Isolated Carbenes
Leyva, Elisa,Barcus, Robert L.,Platz, Matthew S.
, p. 7786 - 7788 (2007/10/02)
Photolysis of diphenyldiazomethane (DPDM) in frozen alcoholic matrices gives ground-state triplet diphenylcarbene (DPC).At 77 K 3DPC reacts primarily with alcohols by OH insertion to give ethers.Photolysis of 3DPC produces an excited carbene 3DPC* which reacts with the matrix by H-atom abstraction to ultimately give alcohol-type products.Secondary photolysis of triplet fluorenylidene at 77 K is not as prevalent as that of 3DPC.
THE EFFECT OF OXYGEN ON THE MATRIX CHEMISTRY OF DIPHENYLCARBENE
Zayas, Jose,Platz, Matthew S.
, p. 2853 - 2856 (2007/10/02)
The effect of oxygen on the matrix chemistry of diphenylcarbene is described.
CHEMISTRY AND KINETICS OF ARYL CARBENES IN METHANOL AT LOW TEMPERATURES.
Wright,Platz
, p. 4175 - 4180 (2007/10/02)
The chemistry and kinetics of six aryl carbenes in polycrystalline methanol are reported. The kinetics were monitored by triplet ESR spectroscopy. Isotope effects were used heavily to probe reaction mechanisms. Several analogues to solution chemistry and kinetics were found. It is concluded that the singlet-triplet energy separation decreases as DBS greater than DPC greater than DBT greater than NC greater than Fl greater than DMA.
Reactions of Triplet Diphenylcarbene by Hydrogen Atom Tunneling in Rigid Media
Platz, Matthew S.,Senthilnathan, V. P.,Wright, Bradford B.,McCurdy, C. W.
, p. 6494 - 6501 (2007/10/02)
Photolysis of diphenyldiazomethane in six matrices (toluene, methylcyclohexane, benzene, diethyl ether, 2-propanol, and cyclohexene) and their deuterated modifications at low temperature gave rise to the metastable triplet ESR spectrum of diphenylcarbene.Chemical and kinetic isotope effects established that the mechanism of the signal decay was hydrogen atom abstraction by the triplet ground state of diphenylcarbene from the matrix host.Analysis of the decay kinetics revealed that this process occurs by quantum mechanical tunneling of the hyfrogen atom.Calculations based upon an Eckart barrier potential reproduced the experimental rate constants faithfully and gave reasonable values for the barrier width and height parameters.It was found that the signal decay in proton and perdeuterated matrices corresponded to sites of very different reactivity.The implications of the tunnel effect for the chemistry observed in low-temperature matrices are discussed.
Temperature and Substituent Effects on Regioselectivity in the Insertion of Arylcarbene into Alcohols
Tomioka, Hideo,Suzuki, Shinji,Izawa, Yasuji
, p. 3156 - 3162 (2007/10/02)
Photolysis of aryldiazomethanes in methanol, ethanol, and 2-propanol gave OH insertion products along with small amounts of CH insertion products at ambient temperature.However, the CH insertion products increased significantly at the expense of the ether as the temperature was lowered.The attempted sensitized decomposition of the diazomethane did not lead to an increase in the CH insertion products presumably because of a rapid singlet-triplet equilibrium.The key intermediate leading to the CH insertion is suggested to be ground-state triplet arylcarbene, based on the accumulated spectroscopic as well as chemical evidence for the intervention of the triplet arylcarbene in the low-temperature photolysis of aryldiazomethanes.Substituents on the phenyl ring also have an appreciable effect on the insertion selectivity.At room temperature, the OH/CH insertion selectivity increased with the electron-donating ability of the substituents.This is interpreted in terms of the substituent effect on the transition state of OH insertion, where there is a deficiency of electrons at the benzylic carbon atom, rather than on the stability of singlet carbene.At low temperature, both electron-donating and -withdrawing substituents facilitate OH insertion, indicating the change in substituents induces a concomitant change in the insertion mechanism, presumably due to decreasing nucleophilicity of carbene with increasing electron-withdrawing ability as well as decreasing proton-donor activity of alcohol with decreasing temperature.This may also reflect the effect of the substituent on the singlet-triplet energy gap.
