Rh(iii)-catalyzed direct C–H/C–H cross-coupling of quinones with arenes assisted by a directing group: identification of carbazole quinones as GSKβ inhibitors

2015 ◽  
Vol 13 (13) ◽  
pp. 3918-3923 ◽  
Author(s):  
Youngtaek Moon ◽  
Yujeong Jeong ◽  
Daehyuk Kook ◽  
Sungwoo Hong
Keyword(s):  
Group Identification ◽  
Cross Coupling ◽  
Wide Range ◽  
Direct Cross ◽  
Directing Group

Rh-catalyzed direct cross-coupling of various (hetero)arenes with quinones is developed. This protocol is effective for a broad range of substrates and a wide range of directing groups.

Ether Synthesis through Reductive Cross-Coupling of Ketones with Alcohols Using Me2SiHCl as both Reductant and Lewis Acid

Synlett ◽  
2017 ◽  
Vol 28 (18) ◽  
pp. 2425-2428 ◽  
Author(s):  
Bill Morandi ◽  
Yong Lee
Keyword(s):  
Functional Groups ◽  
Lewis Acid ◽  
Carbonyl Compounds ◽  
Cross Coupling ◽  
Wide Range ◽  
Direct Cross ◽  
Sterically Hindered ◽  
Polar Functional Groups ◽  
Ether Synthesis ◽  
Dialkyl Ethers

We report that a Lewis acidic silane, Me2SiHCl, can mediate the direct cross-coupling of a wide range of carbonyl compounds with alcohols to form dialkyl ethers. The reaction is operationally simple, tolerates a range of polar functional groups, can be utilized to make sterically hindered ethers, and is extendable to sulfur and nitrogen nucleo­philes.

Directed Nickel-Catalyzed 1,2-Dialkylation of Alkenes

2018 ◽  
Author(s):  
Joseph Derosa ◽  
Vincent A. van der Puyl ◽  
Van T. Tran ◽  
Mingyu Liu ◽  
Keary Engle
Keyword(s):  
Cross Coupling ◽  
Alkyl Halides ◽  
Wide Range ◽  
Directing Group ◽  
Optimized Conditions

A nickel-catalyzed conjunctive cross-coupling of non-conjugated alkenes, alkyl halides, and alkylzinc reagents is reported. Regioselectivity is controlled by chelation of a removable bidentate 8-aminoquinoline directing group. Under optimized conditions, a wide range of 1,2-dialkylated products can be accessed in moderate to excellent yields. To the best of our knowledge, this report represents the first example of three-component 1,2-dialkylation of non-conjugated alkenes to introduce differentiated alkyl fragments.

A direct cross-coupling reaction of electron-deficient alkenes using an oxidizing directing group

2017 ◽  
Vol 53 (3) ◽  
pp. 533-536 ◽  
Author(s):  
Chunbing Yu ◽  
Feifei Li ◽  
Jian Zhang ◽  
Guofu Zhong
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Ruthenium Catalyst ◽  
Cross Coupling Reaction ◽  
Direct Cross ◽  
Directing Group

An oxidant-free cross-coupling of electron-deficient alkenes using an inexpensive ruthenium catalyst is reported, efficiently providing valuable 1,3-butadienes with excellentZ,Eselectivities.

scholarly journals Integrating Allyl Electrophiles into Nickel-Catalyzed Conjunctive Cross-Coupling

2019 ◽  
Author(s):  
Van Tran ◽  
Zi-Qi Li ◽  
Timothy Gallagher ◽  
Joseph Derosa ◽  
Peng Liu ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Cross Coupling ◽  
Building Blocks ◽  
Reductive Elimination ◽  
Mechanistic Studies ◽  
Mild Conditions ◽  
Wide Range ◽  
Directing Group ◽  
Weakly Coordinating ◽  
Analogous Method

Allylation and conjunctive cross-coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel-catalyzed conjunctive cross-coupling with a non-conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate azaheterocycle directing groups, that useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated in the facile reactivity of the β-γ alkene of the starting material, while the ε-ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of analogous method with alkyne substrates. Mechanistic studies reveal the importance of the weakly coordinating directing group in dissociating to allow binding of the allyl moiety to facilitate C(sp<sup>3</sup>)–C(sp<sup>3</sup>) reductive elimination.

Palladium-Catalyzed Csp3–H Bond mono-Aroyloxylation of O-Alkyl Substituted 2,4,6-Trimethoxybenzaldoxime Ethers

Synlett ◽  
2018 ◽  
Vol 29 (09) ◽  
pp. 1249-1255
Author(s):  
Wen-Li Qiao ◽  
Ling-Yan Shao ◽  
Ya-Hua Hu ◽  
Li-Hao Xing ◽  
Ke-Zuan Deng ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Aliphatic Alcohol ◽  
Cross Coupling ◽  
Aliphatic Alcohols ◽  
Aromatic Acid ◽  
Rapid Access ◽  
Site Selectivity ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group

A palladium-catalyzed Csp3–H bond mono-aroyloxylation of O-alkyl substituted oxime ethers has been developed by using 2,4,6-trimethoxybenzaldoxime as an exo-type directing group with exclusive site-selectivity. With the wide range of masked aliphatic alcohol substrates and aromatic acid coupling partners, the protocol allows rapid access to various 2-alkyl substituted glycol derivatives in synthetically useful to good yields. The employed directing group is readily removed, accordingly affording valuable functionalized aliphatic alcohols. When the solvent from hybrid DCE/HFIP to CH3CN, non-directed oxidative cross-coupling is observed between the electron-rich aromatic ring of substrates and aromatic acid partners.

Directed Nickel-Catalyzed 1,2-Dialkylation of Alkenes

2018 ◽  
Author(s):  
Joseph Derosa ◽  
Vincent A. van der Puyl ◽  
Van T. Tran ◽  
Mingyu Liu ◽  
Keary Engle
Keyword(s):  
Cross Coupling ◽  
Alkyl Halides ◽  
Wide Range ◽  
Directing Group ◽  
Optimized Conditions

A nickel-catalyzed conjunctive cross-coupling of non-conjugated alkenes, alkyl halides, and alkylzinc reagents is reported. Regioselectivity is controlled by chelation of a removable bidentate 8-aminoquinoline directing group. Under optimized conditions, a wide range of 1,2-dialkylated products can be accessed in moderate to excellent yields. To the best of our knowledge, this report represents the first example of three-component 1,2-dialkylation of non-conjugated alkenes to introduce differentiated alkyl fragments.

scholarly journals Integrating Allyl Electrophiles into Nickel-Catalyzed Conjunctive Cross-Coupling

2019 ◽  
Author(s):  
Van Tran ◽  
Zi-Qi Li ◽  
Timothy Gallagher ◽  
Joseph Derosa ◽  
Peng Liu ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Cross Coupling ◽  
Building Blocks ◽  
Reductive Elimination ◽  
Mechanistic Studies ◽  
Mild Conditions ◽  
Wide Range ◽  
Directing Group ◽  
Weakly Coordinating ◽  
Analogous Method

Allylation and conjunctive cross-coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel-catalyzed conjunctive cross-coupling with a non-conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate azaheterocycle directing groups, that useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated in the facile reactivity of the β-γ alkene of the starting material, while the ε-ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of analogous method with alkyne substrates. Mechanistic studies reveal the importance of the weakly coordinating directing group in dissociating to allow binding of the allyl moiety to facilitate C(sp<sup>3</sup>)–C(sp<sup>3</sup>) reductive elimination.

Directed Nickel-Catalyzed 1,2-Dialkylation of Alkenes

2018 ◽  
Author(s):  
Joseph Derosa ◽  
Vincent A. van der Puyl ◽  
Van T. Tran ◽  
Mingyu Liu ◽  
Keary Engle
Keyword(s):  
Cross Coupling ◽  
Alkyl Halides ◽  
Wide Range ◽  
Directing Group ◽  
Optimized Conditions

A nickel-catalyzed conjunctive cross-coupling of non-conjugated alkenes, alkyl halides, and alkylzinc reagents is reported. Regioselectivity is controlled by chelation of a removable bidentate 8-aminoquinoline directing group. Under optimized conditions, a wide range of 1,2-dialkylated products can be accessed in moderate to excellent yields. To the best of our knowledge, this report represents the first example of three-component 1,2-dialkylation of non-conjugated alkenes to introduce differentiated alkyl fragments.

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho
Keyword(s):  
Carboxylic Acid ◽  
Building Blocks ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
High Yields ◽  
Vinyl Iodides ◽  
Initial Results

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

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