scholarly journals Complexity-generating hydration reactions via gold-catalyzed addition of boronic acids to alkynes

2012 ◽  
Vol 84 (11) ◽  
pp. 2431-2441 ◽  
Author(s):  
Tom D. Sheppard
Keyword(s):  
Boronic Acid ◽  
Boronic Acids ◽  
Water Molecules ◽  
Primary Alcohols ◽  
One Pot ◽  
Propargylic Alcohols ◽  
Tertiary Alcohols ◽  
Mild Conditions ◽  
Synthetic Intermediates ◽  
Metal Catalyzed

Boronic acids can serve as organic soluble substitutes for water molecules in the metal-catalyzed hydration of alkynes. The Au-catalyzed addition of boronic acids to alkynes provides an alternative method for enolate generation, which proceeds under exceptionally mild conditions. The resulting enolates can be trapped by aldehydes present in the reaction mixture, giving aldol products that can be isolated as cyclic borate esters. These compounds are versatile synthetic intermediates that can be elaborated into a variety of products by transformation of the boron moiety. The Au-catalyzed reaction of boronic acids with propargylic alcohols results in efficient Meyer–Schuster rearrangement to the corresponding enones. The rearrangement of tertiary alcohols gives (E)-enones with moderate to good selectivity, and the addition of a boronic acid to the reaction appears to enhance the level of geometrical control. The rearrangement of primary alcohols to terminal enones also occurs readily in the presence of catalytic Au(I) and a boronic acid, and the resulting terminal enones can be reacted with nucleophiles in one-pot procedures to give a variety of β-substituted ketones.

scholarly journals Selective deoxygenative alkylation of alcohols via photocatalytic domino radical fragmentations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hong-Mei Guo ◽  
Xuesong Wu
Keyword(s):  
High Reactivity ◽  
Methyl Radical ◽  
Primary Alcohols ◽  
Homolytic Cleavage ◽  
One Pot ◽  
Alkyl Radicals ◽  
Tertiary Alcohols ◽  
Mild Conditions ◽  
Radical Generation ◽  
Selective Formation

AbstractThe delivery of alkyl radicals through photocatalytic deoxygenation of primary alcohols under mild conditions is a so far unmet challenge. In this report, we present a one-pot strategy for deoxygenative Giese reaction of alcohols with electron-deficient alkenes, by using xanthate salts as alcohol-activating groups for radical generation under visible-light photoredox conditions in the presence of triphenylphosphine. The convenient generation of xanthate salts and high reactivity of sequential C–S/C–O bond homolytic cleavage enable efficient deoxygenation of primary, secondary and tertiary alcohols with diverse functionality and structure to generate the corresponding alkyl radicals, including methyl radical. Moreover, chemoselective radical monodeoxygenation of diols is achieved via selective formation of xanthate salts.

(DPEPhos)Ni(mesityl)Br: An Air-Stable Pre-Catalyst for Challenging Suzuki–Miyaura Cross-Couplings Leading to Unsymmetrical Biheteroaryls

Synlett ◽  
2018 ◽  
Vol 29 (06) ◽  
pp. 799-804 ◽  
Author(s):  
Mark Stradiotto ◽  
Ryan Sawatzky
Keyword(s):  
Boronic Acid ◽  
Cross Coupling ◽  
Boronic Acids ◽  
Mild Conditions

The successful application of (DPEPhos)Ni(mesityl)Br (C1) as a pre-catalyst in the Suzuki–Miyaura cross-coupling of heteroaryl chlorides or bromides and heteroaryl boronic acids is reported. The use of C1 in this context allows for such reactions to be conducted under mild conditions (2 mol% Ni, 25 °C), including cross-couplings leading to unsymmetrical biheteroaryls. Successful transformations of this type involving problematic pyridinyl boronic acid substrates (10 mol% Ni, 60 °C) are also described.

scholarly journals One-Pot Reductive Acetylation of Aldehydes using 1-Hydrosilatrane in Acetic Acid

SynOpen ◽  
2019 ◽  
Vol 03 (01) ◽  
pp. 1-3 ◽  
Author(s):  
Reuben James ◽  
Sharon Herlugson ◽  
Sami Varjosaari ◽  
Vladislav Skrypai ◽  
Zainab Shakeel ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Organic Synthesis ◽  
Functional Group ◽  
Building Blocks ◽  
Flash Chromatography ◽  
Primary Alcohols ◽  
Facile Synthesis ◽  
One Pot ◽  
Aryl Aldehydes ◽  
Mild Conditions

A one-pot, direct reductive acetylation of aldehydes was achieved under mild conditions using 1-hydrosilatrane as a safe and easily accessible catalyst. Described herein is a facile synthesis that produces acylated primary alcohols that can serve as valuable building blocks for organic synthesis. The method has good functional group tolerance and works for a range of aryl aldehydes, with the notable exception of electron-rich arenes. A library of esters was isolated by flash chromatography in yields as high as 92%.

Metal- and Solvent-free Synthesis of Functionalized Dihydrooxa­zolo[3,2-a]indoles by One-Pot Tandem Assembly of 3H-Indoles and Propargylic Alcohols

Synthesis ◽  
2018 ◽  
Vol 51 (06) ◽  
pp. 1445-1454 ◽  
Author(s):  
Boris Trofimov ◽  
Ludmila Oparina ◽  
Nikita Kolyvanov ◽  
Igor Ushakov ◽  
Anastasiya Mal’kina ◽  
...  
Keyword(s):  
Double Bond ◽  
Solvent Free ◽  
One Pot ◽  
Propargylic Alcohols ◽  
Mild Conditions ◽  
Solvent Free Synthesis

The reaction of 3H-indoles with tertiary propargylic alcohols to give functionalized dihydrooxazolo[3,2-a]indoles in good to excellent yields has been developed. This metal- and solvent-free, one-pot tandem assembly proceeds under mild conditions (22–60 °C) and is regio- and stereoselective: either the Z- or E-isomers (relative to the double bond) are alternatively formed depending on other functionalized substituents on the propargylic alcohols.

Boronic acid catalysis

2019 ◽  
Vol 48 (13) ◽  
pp. 3475-3496 ◽  
Author(s):  
Dennis G. Hall
Keyword(s):  
Transition Metal ◽  
Boronic Acid ◽  
Acid Catalysis ◽  
Boronic Acids ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Although boronic acids are recognized primarily for their utility as reagents in transition metal-catalyzed transformations, other applications are emerging, including their use as reaction catalysts.

scholarly journals Development of a method for the synthesis of 2,4,5-trisubstituted oxazoles composed of carboxylic acid, amino acid, and boronic acid

2017 ◽  
Vol 13 ◽  
pp. 1478-1485 ◽  
Author(s):  
Kohei Yamada ◽  
Naoto Kamimura ◽  
Munetaka Kunishima
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Boronic Acid ◽  
Boronic Acids ◽  
One Pot ◽  
Novel Method ◽  
Coupling Sequence

A novel method for the synthesis of trisubstituted oxazoles via a one-pot oxazole synthesis/Suzuki–Miyaura coupling sequence has been developed. One-pot formation of 5-(triazinyloxy)oxazoles using carboxylic acids, amino acids and a dehydrative condensing reagent, DMT-MM, followed by Ni-catalyzed Suzuki–Miyaura coupling with boronic acids provided the corresponding 2,4,5-trisubstituted oxazoles in good yields.

Synthesis of Nitrile-Bearing Quaternary Centers via an Equilibrium-Driven Transnitrilation and Anion-Relay Strategy

2019 ◽  
Author(s):  
Sebastien Alazet ◽  
Michael West ◽  
Purvish Patel ◽  
Sophie Rousseaux
Keyword(s):  
Building Blocks ◽  
One Pot ◽  
Quaternary Centers ◽  
Synthetic Intermediates

The efficient preparation of nitrile-containing building blocks is of interest due to their utility as synthetic intermediates and their prevalence in pharmaceuticals. As a result, significant efforts have been made to develop methods to access these motifs which rely on safer and non-toxic sources of CN. Herein, we report that 2-methyl-2-phenylpropanenitrile is an efficient, non-toxic, electrophilic CN source for the synthesis of nitrile-bearing quaternary centers via a thermodynamic transnitrilation and anion-relay strategy. This one-pot process leads to nitrile products resulting from the gem-difunctionalization of alkyl lithium reagents.<br>

Dual Roles of TBHP Enabled Regioselective Hydroetherification of (Trifluoromethyl)alkenes with Boronic Acids: Access to α-Trifluoromethyl β-Aryloxy Tertiary Alcohols

Synthesis ◽  
2021 ◽  
Author(s):  
Hengyuan Li ◽  
Chuanle Zhu
Keyword(s):  
Boronic Acids ◽  
Dual Roles ◽  
Tertiary Alcohols ◽  
High Yields

The three-starting materials four-component reaction of (trifluoromethyl)alkenes, TBHP, and boronic acids is reported, delivering various useful α-trifluoromethyl-β-aryloxy tertiary alcohols in high yields and in an exclusively regioselective hydroetherification manner. TBHP serves as both the oxidants and the nucleophiles in this reaction, as well as the O-source of the products.

Asymmetric Synthesis of α-Alkylated γ-Lactam via Nickel/8-Quinim-Catalyzed Reductive Alkyl-Carbamoylation of Unactivated Alkene

Synlett ◽  
2021 ◽  
Author(s):  
Xianqing Wu ◽  
Mohini Shrestha ◽  
Yifeng Chen
Keyword(s):  
Functional Group ◽  
Enantioselective Synthesis ◽  
Chiral Auxiliary ◽  
Alkyl Iodide ◽  
General Strategy ◽  
Chemical Bonds ◽  
Mild Conditions ◽  
Chiral Carbon ◽  
Enantioselective Reaction ◽  
Metal Catalyzed

AbstractChiral-auxiliary-mediated synthesis represents the most frequently used synthetic tool for the induction of chirality on α-position of γ-lactams in organic synthesis. However, the general strategy requires the stoichiometric use of chiral reagents with multiple manipulation steps. Transition-metal-catalyzed asymmetric alkene dicarbofunctionalization using readily available substrates under mild conditions allows the simultaneous construction of two vicinal chemical bonds and a chiral carbon center, hence, gain expedient access to chiral heterocycles. Herein, we disclose a Ni-catalyzed enantioselective reaction of 3-butenyl carbamoyl chloride and primary alkyl iodide enabled by a newly designed chiral 8-quinoline imidazoline ligand (8-Quinim). This protocol features broad functional group tolerance and high enantioselectivities, achieving unprecedented synthesis of chiral nonaromatic heterocycles via catalytic reductive protocol.1 Introduction2 Development of 8-Quinim Ligand3 Nickel/8-Quinim-Catalyzed Enantioselective Synthesis of Chiral α-Alkylated γ-Lactam4 Conclusion and Outlook

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