14097-24-6Relevant academic research and scientific papers
Microwave-assisted solid reaction: Reduction of ketones using sodium borohydride
Chen, Same-Ting
, p. 509 - 511 (1999)
A general and efficient procedure for microwave-assisted reduction of liquid and solid ketones using sodium borohydride without solvents is described. The added support can enhance both the efficiency and chemoselectivity of reduction.
Mono and dimetallic pyrene-imidazolylidene complexes of iridium(III) for the deuteration of organic substrates and the C-C coupling of alcohols
Iba?ez,Poyatos,Peris
, p. 14154 - 14159 (2016)
Three different Ir(iii) complexes with pyrene-containing N-heterocyclic carbenes have been prepared and characterized. Two complexes contain a monodentate pyrene-imidazolylidene ligand, and have the formulae [IrCp?Cl2(pyrene-NHC)] and [IrCp?(CO3)(pyrene-NHC)]. The third complex is a dimetallic complex with a pyrene-di-imidazolylidene bridging ligand, with the formula [{IrCp?(CO3)}2(μ-pyrene-di-NHC)]. The catalytic activity of the three complexes was tested in the H/D exchange of organic substrates, and in the β-alkylation of 1-phenylethanol with primary alcohols. In the deuteration of organic substrates, the carbonate complexes are active even in the absence of additives. The dimetallic complex is the most active one in the catalytic coupling of alcohols, a result that may be interpreted as a consequence of the cooperativity between the two metal centres.
Nickel-catalysed three-component connection reaction of a phenyl group, conjugated dienes, and aldehydes: Stereoselective synthesis of (E)-5-phenyl-3-penten-1-ols and (E)-3-methyl-5-phenyl-3-penten-1-ols
Shibata, Kazufumi,Kimura, Masanari,Kojima, Keisuke,Tanaka, Shuji,Tamaru, Yoshinao
, p. 348 - 353 (2001)
In the presence of 10 mol% of Ni(acac)2, Ph2Zn reacts with 1,3-butadiene and aldehydes at room temperature to give 1-alkyl and 1-aryl substituted (E)-5-phenyl-3-penten-1-ols (3) in good yields. Under similar conditions, the three components of Ph3BZnEt2, isoprene, and aldehydes combine with each other to furnish 1-alkyl and 1-aryl substituted (E)-3-methyl-5-phenyl-3-penten-1-ols (5) in good yields.
Chemistry of ethanediyl S,S-acetals 9-asymmetric synthesis of chiral cis allylic alcohols
Caputo,Ferreri,Palumbo,Pedatella
, p. 1517 - 1522 (1995)
(2Z,1S)-1,3-diphenyl-2-propenol is obtained from the chiral 5,6-dihydro-1,4-dithiin 1b in two steps and 60% enantiomeric excess. Combining our previously reported stereoselective double bond formation and this 1,4 asymmetric induction introduces a new rou
Electronically tuneable orthometalated RuII–NHC complexes as efficient catalysts for C–C and C–N bond formations via borrowing hydrogen strategy
Illam, Praseetha Mathoor,Rit, Arnab
, p. 67 - 74 (2022/01/19)
The catalytic activities of a series of simple and electronically tuneable cyclometalated RuII–NHC complexes (2a–d) were explored in various C–C/N bond formations following the borrowing hydrogen process. Slight modifications in the ligand backbone were noted to tune the activities of these complexes. Among them, the complex 2d featuring a 1,2,4-triazolylidene donor with a 4-NO2–phenyl substituent displayed the highest activity for the coupling of diverse secondary and primary alcohols with a low catalyst loading of 0.01 mol% and a sub-stoichiometric amount of inexpensive KOH base. The efficacy of this simple system was further showcased in the challenging one-pot unsymmetrical double alkylation of secondary alcohols using different primary alcohols. Moreover, the complex 2d also effectively catalyses the selective mono-N-methylation of various aromatic and aliphatic primary amines using methanol to deliver a range of N-methyl amines. Mechanistically, the β-alkylation reaction follows a borrowing hydrogen pathway which was established by the deuterium labelling experiment in combination with various control experiments. Intriguingly, in situ1H NMR and ESI-MS analyses evidently suggested the involvement of a Ru–H species in the catalytic cycle and further, the kinetic studies revealed a first order dependence of the reaction rate on the catalyst as well as the alcohol concentrations.
Reductive Arylation of Amides via a Nickel-Catalyzed Suzuki–Miyaura-Coupling and Transfer-Hydrogenation Cascade
Boit, Timothy B.,Mehta, Milauni M.,Kim, Junyong,Baker, Emma L.,Garg, Neil K.
supporting information, p. 2472 - 2477 (2020/12/03)
We report a means to achieve the addition of two disparate nucleophiles to the amide carbonyl carbon in a single operational step. Our method takes advantage of non-precious-metal catalysis and allows for the facile conversion of amides to chiral alcohols via a one-pot Suzuki–Miyaura cross-coupling/transfer-hydrogenation process. This study is anticipated to promote the development of new transformations that allow for the conversion of carboxylic acid derivatives to functional groups bearing stereogenic centers via cascade processes.
Cu-catalyzed cross-coupling of benzylboronic esters and epoxides
Gierszal, Sophia G.,Barker, Timothy J.
supporting information, (2021/09/20)
A reaction between epoxides and benzylboronic acid pinacol esters is described. CuI was found to be an effective catalyst of this transformation upon activation of the benzylboronic ester with an alkyllithium reagent. The reaction was very efficient and a variety of substituted epoxides were found to be good substrates with good regioselectivity for substitution at the less substituted side of the epoxide. A reaction using an enantioenriched secondary benzylboronic ester was found to not be stereospecific.
Direct conversion of secondary propargyl alcohols into 1,3-di-arylpropanoneviaDBU promoted redox isomerization and palladium assisted chemoselective hydrogenation in a single pot operation
Bera, Mrinal K.,Chandra, Shubhadeep,De, Rimpa,Savarimuthu, S. Antony
, p. 17871 - 17877 (2021/10/12)
Palladium(ii)acetate is found to be an efficient catalyst for the single-step conversion of secondary propargyl alcohols to 1,3-diarylpropanone derivatives under mild basic conditions. The reaction is believed to proceedviaredox isomerisation of secondary propargyl alcohols followed by chemoselective reduction of an enone double bond with formic acid as an adequate hydrogen donor. A large number of 1,3-diarylpropanone derivatives may readily be prepared from a milligram to a multigram scale.
Selective C-alkylation Between Alcohols Catalyzed by N-Heterocyclic Carbene Molybdenum
Liu, Jiahao,Li, Weikang,Li, Yinwu,Liu, Yan,Ke, Zhuofeng
supporting information, p. 3124 - 3128 (2021/09/20)
The first implementation of a molybdenum complex with an easily accessible bis-N-heterocyclic carbene ligand to catalyze β-alkylation of secondary alcohols via borrowing-hydrogen (BH) strategy using alcohols as alkylating agents is reported. Remarkably high activity, excellent selectivity, and broad substrate scope compatibility with advantages of catalyst usage low to 0.5 mol%, a catalytic amount of NaOH as the base, and H2O as the by-product are demonstrated in this green and step-economical protocol. Mechanistic studies indicate a plausible outer-sphere mechanism in which the alcohol dehydrogenation is the rate-determining step.
Manganese-catalyzed homogeneous hydrogenation of ketones and conjugate reduction of α,β-unsaturated carboxylic acid derivatives: A chemoselective, robust, and phosphine-free in situ-protocol
Topf, Christoph,Vielhaber, Thomas
, (2021/07/10)
We communicate a user-friendly and glove-box-free catalytic protocol for the manganese-catalyzed hydrogenation of ketones and conjugated C[dbnd]C[sbnd]bonds of esters and nitriles. The respective catalyst is readily assembled in situ from the privileged [Mn(CO)5Br] precursor and cheap 2-picolylamine. The catalytic transformations were performed in the presence of t-BuOK whereby the corresponding hydrogenation products were obtained in good to excellent yields. The described system offers a brisk and atom-efficient access to both secondary alcohols and saturated esters avoiding the use of oxygen-sensitive and expensive phosphine-based ligands.
