Facile synthesis of axially chiral styrene-type carboxylic acids via palladium-catalyzed asymmetric C–H activation

Palladium-catalyzed asymmetric C–H functionalization to yield axially chiral styrene-type carboxylic acids is described, in which axial chirality and sterically hindered group were incorporated in one-step.

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Palladium-Catalyzed Asymmetric Hydrophosphination of Internal Alkynes: Highly Regio- and Stereoselective Construction of Axially Chiral Phosphines

10.26434/chemrxiv-2021-8rtq4 ◽

2021 ◽

Author(s):

Danqing Ji ◽

Jierui Jing ◽

Yi Wang ◽

Zisong Qi ◽

Fen Wang ◽

...

Keyword(s):

Axial Chirality ◽

Axially Chiral ◽

Internal Alkynes ◽

Trisubstituted Olefins ◽

Palladium Catalyzed ◽

Chiral Phosphines ◽

Kinetic Transformation ◽

Secondary Phosphines

Palladium-catalyzed unprecedented atroposelective hydrophosphination of internal alkynes has been realized using diarylphosphines, affording C-N axially chiral trisubstituted olefins (vinylphosphines) in excellent regioselectiviry, (E)-selectivity, and enantioselectivity. The axial chirality was established via integration of hydrophosphination and dynamic kinetic transformation of the alkynes, with both symmetrical and nonsymmetrical secondary phosphines being applicable. In the latter case, additional P-central chirality has been constructed in good diastereoselectivity.

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Direct and facile synthesis of acyl azides from carboxylic acids using the trichloroisocyanuric acid–triphenylphosphine system

Canadian Journal of Chemistry ◽

10.1139/cjc-2011-0493 ◽

2013 ◽

Vol 91 (3) ◽

pp. 181-185 ◽

Cited By ~ 6

Author(s):

Batool Akhlaghinia ◽

Hamed Rouhi-Saadabad

Keyword(s):

Carboxylic Acids ◽

Practical Method ◽

Facile Synthesis ◽

One Step ◽

Acyl Azides ◽

The One ◽

Trichloroisocyanuric Acid

A mild, efficient, and practical method for the one-step synthesis of acyl azides from carboxylic acids using a safe and inexpensive mixed reagent, trichloroisocyanuric acid–triphenylphosphine, is described.

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Ligand-Enabled γ-C(sp3)–H Olefination of Free Carboxylic Acids

10.26434/chemrxiv.11857857 ◽

2020 ◽

Author(s):

Kiron Kumar Ghosh ◽

Alexander Uttry ◽

Francesca Ghiringhelli ◽

Arup Mondal ◽

Manuel van Gemmeren

Keyword(s):

Reaction Mechanism ◽

Carboxylic Acids ◽

Michael Addition ◽

Kinetic Studies ◽

Wide Range ◽

Palladium Catalyzed

We report the ligand enabled C(sp3)–H activation/olefination of free carboxylic acids in the γ-position. Through an intramolecular Michael-addition, δ-lactones are obtained as products. Two distinct ligand classes are identified that enable the challenging palladium-catalyzed activation of free carboxylic acids in the γ-position. The developed protocol features a wide range of acid substrates and olefin reaction partners and is shown to be applicable on a preparatively useful scale. Insights into the underlying reaction mechanism obtained through kinetic studies are reported.<br>

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Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

10.26434/chemrxiv.12448970.v1 ◽

2020 ◽

Author(s):

Baojian Xiong ◽

Yue Li ◽

Yin Wei ◽

Søren Kramer ◽

Zhong Lian

Keyword(s):

Functional Group ◽

Low Cost ◽

Cross Coupling ◽

Coupling Reactions ◽

Phenol Derivatives ◽

Cross Coupling Reactions ◽

Palladium Catalyzed ◽

One Step ◽

Aryl Tosylates ◽

Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

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