Stereochemical lability of azatitanacyclopropanes: dynamic kinetic resolution in reductive cross-coupling reactions with allylic alcohols

This short review aims to provide an overview of the use of Cp2Ti(III)Cl and other related titanocene(III) species as coordinating reagents in template reactions in the selective preparation of C–C and C–O bonds. These complexes are able to assemble two components to produce powerful reactions possessing high regio-, chemo-, diastereo-, and enantioselectivity. The titanocene templates are divided into five structural types. The chemical transformations by these valuable templates, the substrate scope and mechanistic insights will also be described.1 Introduction2 Precedents for the Coordination of Ti(III) Species to Heteroatoms2.1 Coordination of Compounds with Hydrogen–Heteroatom Bonds to Ti(III) Species2.2 Coordination of Halogens to Ti(III) Species3 Types of Titanocene Templates4 Template Type I Mediated Organic Reactions4.1 Methylenecyclopropanation of Allylic Alcohols4.2 Base-Free O-Acylation of Alcohols and Phenol4.3 Epoxidation of Allylic Alcohols5 Template Type II Mediated Organic Reactions5.1 Ketone–Nitrile Cross-Coupling Reactions5.2 Imine–Nitrile Cross-Coupling Reactions5.3 Reductive Alkylation of Enones with Activated Alkenes6 Template Type III Mediated Organic Reactions6.1 Pinacol Coupling of Ketones7 Template Type IV Mediated Organic Reactions7.1 Michael-Type Addition of Aldehydes to Conjugated Enals7.2 Allylation, Crotylation, and Prenylation7.3 Barbier-Type Progargylation and Allenylation8 Template Type V Mediated Organic Reactions8.1 Protection of Alcohols as 2-O-THF and 2-O-THP Ethers8.2 Pinacol Coupling of Aldehydes8.3 McMurry Couplings9 Conclusions and Perspectives

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Palladium-Catalyzed Cross Coupling Reactions of β-Iodo-β,γ-enones with Organozinc Chlorides

The Journal of Organic Chemistry ◽

10.1021/jo974001u ◽

1997 ◽

Vol 62 (6) ◽

pp. 1908-1908

Author(s):

Fen-Tair Luo ◽

Li-Chen Hsieh

Keyword(s):

Cross Coupling ◽

Coupling Reactions ◽

Cross Coupling Reactions ◽

Palladium Catalyzed

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Palladium catalyzed cross-coupling reactions of difunctional derivatives Bu3SnArBr. Synthesis of regioregular poly(3-alkylthiophenes) and poly(4-alkyl 2,2'-bithiophenes) with high molecular weights

Journal de Chimie Physique ◽

10.1051/jcp:1998259 ◽

1998 ◽

Vol 95 (6) ◽

pp. 1250-1253 ◽

Cited By ~ 5

Author(s):

J.-P. Lère-Porte ◽

J. J.E. Moreau ◽

C. Torreilles

Keyword(s):

Cross Coupling ◽

Coupling Reactions ◽

Molecular Weights ◽

Cross Coupling Reactions ◽

Regioregular Poly ◽

Palladium Catalyzed

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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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An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction

10.26434/chemrxiv.12582284.v1 ◽

2020 ◽

Author(s):

Chet Tyrol ◽

Nang Yone ◽

Connor Gallin ◽

Jeffery Byers

Keyword(s):

Coupling Reaction ◽

Cross Coupling ◽

Coupling Reactions ◽

Radical Intermediates ◽

Cross Coupling Reactions ◽

Cross Coupling Reaction ◽

Boronic Esters ◽

Carbon Centered Radical ◽

Iron Based ◽

High Yields

By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates.

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