Reduction of Carboxylic Acids and Their Derivatives to Alcohols, Ethers, and Amines DOI
Hélio M. T. Albuquerque

Elsevier eBooks, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Language: Английский

TiCl4-mediated deoxygenative reduction of aromatic ketones to alkylarenes with ammonia borane DOI
Yongjun Zang,

Yunfeng Ma,

Qilin Xu

et al.

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(5), P. 932 - 939

Published: Jan. 1, 2024

A rapid and mild protocol for the exhaustive deoxygenation of various aromatic ketones to corresponding alkanes using AB as a reductant TiCl 4 catalyst.

Language: Английский

Citations

5
Catalyst- and Stoichiometry-Dependent Deoxygenative Reduction of Esters to Ethers or Alcohols with Borane–Ammonia DOI
P. Veeraraghavan Ramachandran,

Abdulkhaliq A. Alawaed,

Henry J. Hamann

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(37), P. 6902 - 6906

Published: Sept. 10, 2023

A facile and selective room temperature deoxygenation of both aromatic aliphatic carboxylic esters to ethers has been achieved by regulating the stoichiometry reductant, BH3–NH3, catalyst, TiCl4. This first, practical borane-mediated process is compatible with various potentially sensitive functional groups applicable deoxygenative ether formation from typically challenging acid esters. Substituting BF3–Et2O as catalyst alters reaction pathway, reducing alcohols. Mechanistic insights are provided NMR spectroscopy, deuterium labeling, kinetic isotope studies.

Language: Английский

Citations

12
Balancing Lewis Acidity and Carbocation Stability for the Selective Deoxyhalogenation of Aryl Carbonyls and Carbinols DOI
P. Veeraraghavan Ramachandran,

Abdulkhaliq A. Alawaed,

Henry J. Hamann

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(25), P. 4650 - 4655

Published: June 15, 2023

Deoxyhalogenation of aryl aldehydes, ketones, carboxylic acids, and esters has been achieved utilizing an appropriate metal halide Lewis acid acting as a carbonyl activator halogen carrier in combination with borane-ammonia the reductant. Selectivity is accomplished by matching stability carbocation intermediate effective acidity acid. Substituents substitution patterns significantly influence requisite solvent/Lewis combination. Logical combinations these factors have also applied for regioselective conversion alcohols to alkyl halides.

Language: Английский

Citations

11
Borane-Pyridine: An Efficient Catalyst for Direct Amidation DOI Creative Commons
P. Veeraraghavan Ramachandran, Aman Singh,

Harry A. Walker

et al.

Molecules, Journal Year: 2024, Volume and Issue: 29(1), P. 268 - 268

Published: Jan. 4, 2024

Borane-pyridine acts as an efficient (5 mol%) liquid catalyst, providing improved solubility for the direct amidation of a wide range aromatic and aliphatic carboxylic acids amines to form secondary tertiary carboxamides. Tolerance potentially incompatible halo, nitro, alkene functionalities has been demonstrated.

Language: Английский

Citations

4
Synthesis of the aggregation pheromone of Tribolium castaneum DOI Creative Commons

Biyu An,

Xueyang Wang,

Ao Jiao

et al.

Beilstein Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 21, P. 510 - 514

Published: March 6, 2025

Tribolium castaneum Herbst is a destructive stored product pest. The aggregation pheromone of this pest was prepared via new and effective strategy. key steps include the ring-opening reaction chiral 2-methyloxirane, stereospecific inversion secondary tosylate, Li2CuCl4-catalyzed coupling tosylate with Grignard reagent, oxidation RuCl3/NaIO4.

Language: Английский

Citations

0
Titanium Tetrachloride-Assisted Direct Esterification of Carboxylic Acids DOI Creative Commons

Palmira Alessia Cavallaro,

Marzia De Santo,

Marianna Greco

et al.

Molecules, Journal Year: 2024, Volume and Issue: 29(4), P. 777 - 777

Published: Feb. 8, 2024

Ester compounds, widely found in pharmaceutical and natural products, play a crucial role organic synthesis, prompting the development of numerous methods for their synthesis. An important chemical approach synthesizing esters from carboxylic acids involves activation carboxyl function, requiring conversion hydroxyl group into suitable leaving group. This paper presents findings our investigations an efficient method producing alcohols, using Lewis acid titanium tetrachloride. Titanium tetrachloride has proven highly effective as coupling reagent one-pot formation alcohols operating under mild neutral conditions. Notably, reaction eliminates need bases, yielding high purity yields. The is efficient, even with long-chain acids, operates well primary dichloromethane. Steric hindrance, potentially present moderate effect on reaction. Alcohol substrates that easily form stable carbocations require, instead, use non-polar solvents like hexane

Language: Английский

Citations

3
Titanium-Mediated Reduction of Carboxamides to Amines with Borane–Ammonia DOI Creative Commons
P. Veeraraghavan Ramachandran,

Abdulkhaliq A. Alawaed,

Aman Singh

et al.

Molecules, Journal Year: 2023, Volume and Issue: 28(12), P. 4575 - 4575

Published: June 6, 2023

In this study, the successful titanium tetrachloride-catalyzed reduction of aldehydes, ketones, carboxylic acids, and nitriles with borane-ammonia was extended to (deoxygenation) a variety aromatic aliphatic pri-, sec- tert-carboxamides, by changing stoichiometry catalyst reductant. The corresponding amines were isolated in good excellent yields, following simple acid-base workup.

Language: Английский

Citations

8
TiF4-catalyzed direct amidation of carboxylic acids and amino acids with amines DOI Creative Commons

Abdulkhaliq A. Alawaed,

P. Veeraraghavan Ramachandran

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(9), P. 1915 - 1919

Published: Jan. 1, 2024

Catalytic titanium tetrafluoride enables the direct amidation of aromatic and aliphatic carboxylic acids N -protected amino with amines, yielding structurally diverse carboxamide peptide products.

Language: Английский

Citations

3
Reduction of esters to alcohols and iodides using aminodiborane (μ-NH2B2H5): scope and mechanistic investigations DOI
Abhishek Nair, Vikas Tiwari,

Sambhav Rath

et al.

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(74), P. 11117 - 11120

Published: Jan. 1, 2023

Herein, we report an efficient methodology for the reduction of esters, carbonates, and anhydrides to alcohols using in situ generated aminodiborane from iodine ammonia borane. This also finds use transformation esters iodides by varying stoichiometry reagents. The protocol has broad substrate scope with excellent yields. method is useful synthesizing pharmaceutically industrially important compounds such as a Cinacalcet precursor, Streptoindole analogue, 1,4-pentanediol. Control studies DFT calculations carried out study mechanism indicate that dioxaborinamine intermediate formed during reaction.

Language: Английский

Citations

7
Aryl carbonyls and carbinols as proelectrophiles for Friedel–Crafts benzylation and alkylation DOI Creative Commons
P. Veeraraghavan Ramachandran,

Randy Lin,

Abdulkhaliq A. Alawaed

et al.

RSC Advances, Journal Year: 2024, Volume and Issue: 14(22), P. 15554 - 15559

Published: Jan. 1, 2024

Friedel–Crafts benzylation/alkylation using benzylic alcohols and aryl carbonyls as proelectrophiles is achieved borane-ammonia TiCl 4 .

Language: Английский

Citations

2