Alkene Difunctionalization Directed by Free Amines: Diamine Synthesis via Nickel-Catalyzed 1,2-Carboamination

2021 ◽  
Author(s):  
Taeho Kang ◽  
José Manuel González ◽  
Zi-Qi Li ◽  
Klement Foo ◽  
Peter Cheng ◽  
...  
Keyword(s):  
Nickel Catalyst ◽  
Room Temperature ◽  
Kinetic Studies ◽  
Fine Tuning ◽  
Secondary Amines ◽  
Protecting Group ◽  
Wide Range ◽  
Leaving Group ◽  
Primary And Secondary Amines ◽  
Reaction Proceeds

A versatile method to access differentially substituted 1,3- and 1,4-diamines via a nickel-catalyzed three-component 1,2-carboamination of alkenyl amines with aryl/alkenylboronic ester nucleophiles and N–O electrophiles is reported. The reaction proceeds efficiently with free primary and secondary amines without needing a directing auxiliary or protecting group, and is enabled by fine-tuning the leaving group on the N–O reagent. The transformation is highly regioselective and compatible with a wide range of coupling partners and alkenyl amine substrates, all performed at room temperature. A series of kinetic studies support a mechanism in which alkene coordination to the nickel catalyst is turnover-limiting.

Regio- and Stereoselective (SN2) N-, O-, C- and S-Alkylation using Trialkyl Phosphates

Synthesis ◽  
2021 ◽  
Author(s):  
Amit banerjee ◽  
Tomohiro Hattori ◽  
Hisashi Yamamoto
Keyword(s):  
Room Temperature ◽  
Alkylating Agents ◽  
Alkyl Halides ◽  
Back Side ◽  
Alkyl Groups ◽  
Wide Range ◽  
Leaving Group ◽  
Reaction Proceeds ◽  
Trialkyl Phosphates ◽  
Trialkyl Phosphate

Bimolecular nucleophilic substitution (S N 2) is one of the most known fundamental reactions in organic chemistry to generate new molecules from two molecules. In principle, a nucleophile attacks from the back side of an alkylating agent having a suitable leaving group, most commonly using a halide. However, alkyl halides are expensive, very harmful, toxic and not so stable which makes them problematic for laboratory use. In contrast, trialkyl phosphates are cheap, readily accessible, stable at room temperature, under air, and are easy to handle but rarely used as alkylating agents in organic synthesis. Here, we describe a mild, straightforward and powerful method for nucleophilic alkylation of various nucleophiles such as N-, O-, C- and S- using readily available trialkyl phosphate. The reaction proceeds smoothly with excellent yield and quantitative yield in many cases and covers a wide range of substrates. Further, the rare stereoselective transfer of secondary alkyl groups has been achieved with inversion of configuration of chiral centers (up to >99% ee).

Nucleophilic attack on the carbon–carbon double bond. I. Reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene

1986 ◽  
Vol 64 (12) ◽  
pp. 2274-2278 ◽  
Author(s):  
Kenneth T. Leffek ◽  
Urszula Maciejewska
Keyword(s):  
Order Reaction ◽  
Secondary Amines ◽  
Nucleophilic Attack ◽  
Ammonium Ions ◽  
Third Order ◽  
First Order ◽  
Enthalpy Of Activation ◽  
Catalysed Reaction ◽  
Primary And Secondary Amines ◽  
Reaction Proceeds

The reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene (1) in acetonitrile solvent gives first 2,2-di(4-nitrophenyl)-1-fluoro-1-aminoethene (2) and then 2,2-di(4-nitrophenyl)-1,1-difluoro-1-aminoethane (3). With excess amine, pseudo-first-order rate constants for the production of 2 were measured, which showed a second-order reaction, together with a catalysed third-order reaction. In addition to the reagent amines, the reaction is also catalysed by tertiary amines and bases such as oxalate and acetate, but not by chloride and perchlorate, nor by ammonium ions. The enthalpy of activation for the reaction of piperidine with 1 in acetonitrile is 3.7 kcalmol−1, but for the catalysed reaction an apparent value of −2.2 kcal mol−1 was obtained. It is concluded that the reaction proceeds via a pre-equilibrium to a zwitterion, followed by another equilibrium giving a carbanion that yields the product (2) by a rate-determining cleavage of the carbon–fluorine bond.

N-Heterocyclic Carbene-Catalyzed Synthesis of Ynones via C–H Alkynylation of Aldehydes with Alkynyliodonium Salts

2019 ◽  
Author(s):  
Adam A. Rajkiewicz ◽  
Natalia Wojciechowska ◽  
Marcin Kalek
Keyword(s):  
Density Functional ◽  
Bond Formation ◽  
Kinetic Studies ◽  
Density Functional Theory Calculations ◽  
Hypervalent Iodine ◽  
Functional Theory ◽  
Leaving Group ◽  
13C Labelling ◽  
Reaction Proceeds ◽  
Mechanism Of The Reaction

Alkynylation of aldehydes with alkynyl(aryl)iodonium salts catalyzed by an N-heterocyclic carbene (NHC) has been developed. The application of the organocatalyst and the hypervalent iodine group-transfer reagent allowed for metal-free C–H functionalization and C–C bond formation. The reaction proceeds under exceptionally mild conditions, at –40 ⁰C and in the presence of an amine base, providing access to an array of heteroaryl-propargyl ketones containing various substituents in good to excellent yields. The mechanism of the reaction was investigated by means of both experiments and density functional theory calculations. 13C-labelling and computations determined that the key alkynyl transfer step occurs via an unusual direct SN2 substitution of iodine-based leaving group by Breslow intermediate nucleophile at an acetylenic carbon. Moreover, kinetic studies revealed that the turnover-limiting step of the catalytic cycle is the generation of the Breslow intermediate, whereas the subsequent C–C bond-formation is a fast process. These results were fully reproduced and rationalized by the computed full free energy profile of the reaction, showing that the largest energy span is located between protonated NHC and the transition state for the carbene attack on the aldehyde substrate.<br>

Reactions of Perimidin-4-ones and -6-ones with amines

1977 ◽  
Vol 30 (9) ◽  
pp. 2063 ◽  
Author(s):  
DW Cameron ◽  
EL Samuel
Keyword(s):  
Double Bond ◽  
Room Temperature ◽  
Significant Degree ◽  
Secondary Amines ◽  
Nucleophilic Attack ◽  
Side Chain ◽  
Amino Compounds ◽  
Primary And Secondary Amines ◽  
Benzenoid Ring

π-Deficient perimidin-4- and -6-one systems reacted readily with primary and secondary amines at room temperature. Nucleophilic attack occurred not only at the enone double bond, but also at positions 7 and 9 on the benzenoid ring. Highly coloured mono-, di- or tri-aminated derivatives were thereby obtained. A significant degree of bond fixation was indicated. Side-chain amination of 9-methyl substituents was observed, analogous to processes encountered in quinone chemistry. On continued contact with amine the products were converted partly into 9-formyl derivatives and partly into 9-amino compounds.

Oxidative coupling of amines and carbon monoxide catalyzed by palladium complexes. Mono- and double carbonylation reactions promoted by iodine compounds

1990 ◽  
Vol 68 (9) ◽  
pp. 1544-1547 ◽  
Author(s):  
Ilan Pri-Bar ◽  
Howard Alper
Keyword(s):  
Carbon Monoxide ◽  
Oxidative Coupling ◽  
Room Temperature ◽  
Palladium Complexes ◽  
Secondary Amines ◽  
Primary Amines ◽  
Palladium Acetate ◽  
Principal Product ◽  
Iodine Compounds ◽  
Primary And Secondary Amines

Iodine is an effective promoter for the carbonylation of primary and secondary amines to ureas using palladium acetate as the catalyst and a base (e.g. K2CO3) in acetonitrile (3 h at 95 °C and 2.7 atm). Oxamides are formed in excellent yields when secondary amines are carbonylated in the presence of iodide ion and oxygen, while primary amines give ureas as the principal product at 95 °C, and oxamide at room temperature. Keywords: oxamides, ureas, double carbonylation, amines.

TRIMETHYL ORTHOBORATE – AMINE INCLUSION COMPOUNDS

1962 ◽  
Vol 40 (9) ◽  
pp. 1805-1815
Author(s):  
D. M. Young ◽  
C. D. Anderson
Keyword(s):  
Vapor Pressure ◽  
Inclusion Compounds ◽  
Room Temperature ◽  
Secondary Amines ◽  
Crystalline Inclusion ◽  
X Ray Diffraction ◽  
Crystalline Inclusion Compounds ◽  
X Ray ◽  
New Class ◽  
Primary And Secondary Amines

A new class of non-stoichiometric crystalline inclusion compounds has been discovered, having the general formula[Formula: see text]where 0.5 < n < 1.0 and 0 < x < 3 depending on the method of preparation and on the nature of the amine and solvent. Such compounds have been prepared with ammonia and a variety of primary and secondary amines. Among the solvents which can be incorporated into the crystals are alcohols, ketones, ethers, esters, nitriles, nitroparaffins, and hydrocarbons. Such compounds are also formed by triphenyl orthoborate, with 1.7 < n < 2.4 and 1.2 < x < 1.6.The incorporated solvent has been shown to exert a definite vapor pressure. Furthermore, many of the compounds sublime at room temperature to form large transparent crystals which also contain incorporated solvent. The mechanism probably involves dissociation, followed by reassociation on the walls of the vessel. Preliminary X-ray diffraction measurements suggest that the trimethyl orthoborate – ammonia inclusion compounds have essentially the same crystal lattice as pure trimethyl orthoborate – ammonia.

Mechanistic Studies of Hydrogen Release from Solid Amine Borane Materials

2006 ◽  
Vol 927 ◽  
Author(s):  
Mark Bowden ◽  
Tim Kemmitt ◽  
Wendy Shaw ◽  
Nancy Hess ◽  
John Linehan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Kinetic Studies ◽  
Structural Data ◽  
Ammonia Borane ◽  
Hydrogen Release ◽  
Hydrogen Atoms ◽  
Reaction Proceeds ◽  
In Situ Nmr Spectroscopy ◽  
In Situ Nmr

ABSTRACTAmmonia borane (NH3BH3) is a molecular solid with a high volumetric and gravimetric density of hydrogen. We report room temperature structural data which shows how the freely rotating NH3 and BH3 groups allow a N-H…H-B dihydrogen bond in which hydrogen atoms on adjacent molecules are separated by only 1.90Å. The initial decomposition of ammonia borane at 80-100°C into (NH2BH2)n and H2 has been studied by in-situ nmr spectroscopy and kinetic studies using isotopic substitution. The reaction proceeds by a bimolecular pathway involving a [NH3BH2NH3]+BH4− intermediate with an activation energy of 136kJmol−1.

Catalyst- and solvent-free efficient access to N-alkylated amines via reductive amination using HBpin

2020 ◽  
Vol 18 (20) ◽  
pp. 3853-3857
Author(s):  
Vipin K. Pandey ◽  
Somnath Bauri ◽  
Arnab Rit
Keyword(s):  
Room Temperature ◽  
Reductive Amination ◽  
Solvent Free ◽  
Secondary Amines ◽  
One Pot ◽  
Efficient Access ◽  
Wide Range ◽  
General Method

A general method for catalyst- and solvent-free room temperature reductive amination has been developed and it efficiently delivers a wide range of sterically and electronically diverse secondary amines in one-pot.

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