Alcohol Oxidation Level Research Articles

Enantioselective Ruthenium-BINAP-Catalyzed Carbonyl Reductive Coupling of Alkoxyallenes: Convergent Construction of syn-sec,tert-Diols via (Z)-σ-Allylmetal Intermediates.

The first catalytic enantioselective ruthenium-catalyzed carbonyl reductive couplings of allene pronucleophiles is described. Using an iodide-modified ruthenium-BINAP-catalyst and O-benzhydryl alkoxyallene 1a, carbonyl (α-alkoxy)allylation occurs from the alcohol or aldehyde oxidation level to form enantiomerically enriched syn-sec,tert-diols. Internal chelation directs intervention of (Z)-σ-alkoxyallylruthenium isomers, which engage in stereospecific carbonyl addition.

Construction of All-Carbon Chiral Quaternary Centers through CuI -Catalyzed Enantioselective Reductive Hydroxymethylation of 1,1-Disubstituted Allenes with CO2.

A catalytic enantioselective construction of all-carbon chiral quaternary centers through reductive hydroxymethylation of 1,1-disubstituted allenes with CO2 has been developed. In the presence of a copper/Mandyphos catalyst, CO2 is transformed into an alcohol oxidation level by an asymmetric reductive C-C bond formation with allenes by using hydrosilane (HSi(OMe)2 Me) as a reductant. The resulting chiral homoallylic alcohols are versatile synthetic intermediates and can be conveniently converted into a variety of useful chiral chemicals.

ChemInform Abstract: Copper‐Catalyzed C—C Bond‐Forming Transformation of CO2 to Alcohol Oxidation Level: Selective Synthesis of Homoallylic Alcohols from Allenes, CO2, and Hydrosilanes.

AbstractReaction and work‐up conditions for the regioselective transformation of various 1‐substituted, 1,1‐ and 1,3‐disubstituted allenes with carbon dioxide to homoallyl alcohol derivatives are developed which tolerate numerous functional groups.

Copper-catalyzed C-C bond-forming transformation of CO2 to alcohol oxidation level: selective synthesis of homoallylic alcohols from allenes, CO2, and hydrosilanes.

A highly selective carbon-carbon bond-forming transformation of carbon dioxide (CO2) to alcohol oxidation level has been disclosed. By employing a copper/bisphosphine catalyst system and hydrosilanes as mild and easy-to-handle reducing agents, various allenes can be reacted with CO2 to regioselectively obtain homoallylic alcohols. Esters and other reducible functionalities on the allenes remain intact during the reaction, whereas CO2 is reduced to alcohol oxidation level.

ChemInform Abstract: Cu(II)‐Catalyzed Oxidative Esterification of 2‐Carbonyl Substituted Phenols from the Alcohol Oxidation Level.

AbstractA copper‐catalyzed esterification of 2‐carbonyl substituted phenols with a range of benzylic and aliphatic alcohols using tert‐butyl hydroperoxide as convenient oxidant is presented.

ChemInform Abstract: Palladium‐Catalyzed Direct Acylation of Ketoximes and Aldoximes from the Alcohol Oxidation Level Through C—H Bond Activation.

AbstractThe title reaction represents a catalytic alternative to classical Friedel‐Crafts acylation and proceeds with excellent levels of regio‐ and chemoselectivity and high functional group tolerance.

Cu(II)-catalyzed oxidative esterification of 2-carbonyl substituted phenols from the alcohol oxidation level

A copper-catalyzed oxidative esterification of 2-carbonyl substituted phenols from the alcohol oxidation level is described. This protocol represents direct access to a range of 2-carbonylated aryl benzoate derivatives, which are important building blocks in the synthesis of natural and pharmacological compounds.

Palladium‐Catalyzed Direct Acylation of Ketoximes and Aldoximes from the Alcohol Oxidation Level through C–H Bond Activation

AbstractA highly efficient palladium‐catalyzed oxidative ortho‐acylation of O‐methyl ketoximes and O‐methyl aldoximes with benzylic and aliphatic alcohols from the alcohol oxidation level is described. This protocol potentially provides new opportunities to use readily available alcohols as starting materials for catalytic reactions, and represents a catalytic alternative to transcend the barriers imposed by classical Friedel–Crafts acylation.

ChemInform Abstract: Direct Acylation of N‐Benzyltriflamides from the Alcohol Oxidation Level via Palladium‐Catalyzed C—H Bond Activation.

AbstractThe Pd‐catalyzed acylation of triflamides (I) and (IV) with alcohols (II) in the presence of tBuOOH leads selectively to ortho‐monoacylated products (III) and (V), whilst the analogous reaction of triflamide (VI) affords a mixture of mono‐ and diacylated products.

ChemInform Abstract: Formation of C—C Bonds via Ruthenium‐Catalyzed Transfer Hydrogenation

AbstractReview: 91 refs.

Asymmetric Synthesis of (+)-trans-Aerangis Lactone

Asymmetric synthesis of (+)-trans-aerangis lactone was achieved from commercially available 1-hexanol or 1-hexanal in four steps via iridium-catalyzed diastereoselective and enantioselective carbonyl crotylation from the alcohol or aldehyde oxidation level, and ruthenium-catalyzed olefin metathesis.

Direct acylation of N-benzyltriflamides from the alcohol oxidation level via palladium-catalyzed C–H bond activation

A palladium-catalyzed ortho-acylation of N-benzyltriflamides from the alcohol oxidation level via C-H bond activation is described. These transformations have been applied to a wide range of substrates, and typically proceed with excellent levels of chemoselectivity and with high functional group tolerance.

ChemInform Abstract: Diastereo‐ and Enantioselective Iridium‐Catalyzed Carbonyl Propargylation from the Alcohol or Aldehyde Oxidation Level: 1,3‐Enynes as Allenylmetal Equivalents.

AbstractIn the presence of SEGPHOS catalysts, the reaction proceeds generally with high anti‐selectivity regardless whether alcohols or aldehydes are used.

Formation of C-C bonds via ruthenium-catalyzed transfer hydrogenation().

Ruthenium-catalyzed transfer hydrogenation of diverse π-unsaturated reactants in the presence of aldehydes provides products of carbonyl addition. Dehydrogenation of primary alcohols in the presence of the same π-unsaturated reactants provides identical products of carbonyl addition. In this way, carbonyl addition is achieved from the alcohol or aldehyde oxidation level in the absence of stoichiometric organometallic reagents or metallic reductants. In this account, the discovery of ruthenium-catalyzed C-C bond-forming transfer hydrogenations and the recent development of diastereo- and enantioselective variants are discussed.

Diastereo‐ and Enantioselective Iridium‐Catalyzed Carbonyl Propargylation from the Alcohol or Aldehyde Oxidation Level: 1,3‐Enynes as Allenylmetal Equivalents

In the presence of SEGPHOS catalysts, the reaction proceeds generally with high anti-selectivity regardless whether alcohols or aldehydes are used.

Diastereo‐ and Enantioselective Iridium‐Catalyzed Carbonyl Propargylation from the Alcohol or Aldehyde Oxidation Level: 1,3‐Enynes as Allenylmetal Equivalents

Chiralitätstransfer: Die Behandlung von konjugierten Eninen mit Alkoholen und einem Iridium-Katalysator mit Segphos-Ligand führt zur Bildung von Aldehyd-Allenyl-Iridium-Komplexen und enantiomerenangereicherten Produkten einer Carbonyl-anti-(α-methyl)propargylierung (siehe Schema). Die gleichen Produkte werden mit Aldehyden nach Transferhydrierung mit Ameisensäure als Reduktionsmittel erhalten.

Consecutive iridium catalyzed C–C and C–H bond forming hydrogenations for the diastereo- and enantioselective synthesis of syn-3-fluoro-1-alcohols: C–H (2-fluoro)allylation of primary alcohols

Commercially available (2-fluoro)allyl chloride serves as an efficient allyl donor in highly enantioselective iridium catalyzed carbonyl (2-fluoro)allylations from the alcohol or aldehyde oxidation level via transfer hydrogenation. Diastereoselective Crabtree hydrogenation of the resulting homoallylic alcohols provides syn-3-fluoro-1-alcohols.

ChemInform Abstract: Catalytic Enantioselective Grignard Nozaki—Hiyama Methallylation from the Alcohol Oxidation Level: Chloride Compensates for π‐Complex Instability.

AbstractThe iridium‐catalyzed reaction of methallyl chloride (II) with alcohols (I) gives rise to desired alkenes (III) with high enantioselectivity.

ChemInform Abstract: Formation of C—C Bonds via Iridium‐Catalyzed Hydrogenation and Transfer Hydrogenation

AbstractReview: 310 refs.

Unlocking Hydrogenation for C-C Bond Formation: A Brief Overview of Enantioselective Methods.

Hydrogenation of π-unsaturated reactants in the presence of carbonyl compounds or imines promotes reductive C-C coupling, providing a byproduct-free alternative to stoichiometric organometallic reagents in an ever-increasing range of C=X (X = O, NR) additions. Under transfer hydrogenation conditions, hydrogen exchange between alcohols and π-unsaturated reactants triggers generation of electrophile-nucleophile pairs, enabling carbonyl addition directly from the alcohol oxidation level, bypassing discrete alcohol oxidation and generation of stoichiometric byproducts.