| 1. |
|
|
| 2. |
- Akkarasamiyo, Sunisa, et al.
(författare)
-
Intermolecular Stereospecific Substitution of Underivatized Enantioenriched Secondary Alcohols by Organocatalysis
- 2019
-
Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 58:50, s. 17908-17910
-
Tidskriftsartikel (refereegranskat)abstract
- The stereospecific substitution of non-derivatized and non-allylic enantioenriched alcohols with only water as a by-product would enable the use of readily available alcohols as substrates for green and sustainable transformations. However, the poor leaving group ability of the OH group has hampered the development of such a process. Denton and co-workers recently described the use of (2-hydroxybenzyl)diphenylphosphine oxide as a catalyst of a redox-neutral and zero-waste-generating Mitsunobu reaction. This innovative process constitutes the first intermolecular stereospecific substitution of non-allylic alcohols, and might find industrial applications.
|
|
| 3. |
- Akkarasamiyo, Sunisa, et al.
(författare)
-
Nickel-Catalyzed Stereospecific Deoxygenation of trans- Aromatic Epoxides to (Z)-Alkenes : An Efficient Route to Access (Z)-Cinnamic Acid Derivatives
- 2024
-
Ingår i: Asian journal of organic chemistry, ISSN 2193-5807; EISSN 2193-5815. - 2193-5807 .- 2193-5815. ; 13:5, s. e202400009-
-
Tidskriftsartikel (refereegranskat)abstract
- A stereospecific deoxygenation of trans-epoxy cinnamic acid derivatives to access (Z)-cinnamamides, (Z)-cinnamyl alcohol and (Z)-cinnamyl amines using a catalytic system based on nickel triflate and triphenylphosphine has been developed. The desired products were obtained in good to excellent yield (up to 92 % isolated yield) and excellent stereospecificity (Z : E ratio up to>99 : 1). The transformation has a broad functional group tolerance including amides, amines, alcohols and esters. The power of the methodology was demonstrated in the key step of the total synthesis of biologically active natural product, N-cis-feruloyl tyramine from readily available trans-ferulic acid. A reaction mechanism involving activation of epoxide via coordination of the oxygen atom and the neighboring O- or N-atoms to the nickel catalyst and formation of Ph3P-carbon bond is proposed. This method is important for synthesis of highly desirable functionalized (Z)-alkenes from readily available (E)-alkenes. © 2024 Wiley-VCH GmbH.
|
|
| 4. |
- Akkarasamiyo, Sunisa, et al.
(författare)
-
Nickel-Catalyzed Suzuki-Miyaura Cross-Coupling Reaction of Naphthyl and Quinolyl Alcohols with Boronic Acids
- 2019
-
Ingår i: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 21:12, s. 4782-4787
-
Tidskriftsartikel (refereegranskat)abstract
- A nickel-catalyzed C(sp(3))-C(sp(2)) Suzuki cross-coupling of arylboronic acids and (hetero)naphthyl alcohols has been developed. A Ni(dppp) Cl-2 complex showed the highest efficiency and broadest substrate scope. High functional group tolerance has been achieved where 35 compounds could be generated in good to excellent yields, including both primary and secondary benzylic alcohols. Mechanistic studies using multiple NMR techniques as well as ESI-HRMS showed that the C-O cleavage is facilitated by an activation of the benzylic alcohol through formation of a boronic ester intermediate.
|
|
| 5. |
- Akkarasamiyo, Sunisa, et al.
(författare)
-
Synthesis of (Z)-Cinnamate Esters by Nickel-Catalyzed Stereoinvertive Deoxygenation of trans-3-Arylglycidates
- 2022
-
Ingår i: Synlett. - : Georg Thieme Verlag KG. - 0936-5214 .- 1437-2096. ; 33:14, s. 1353-1356
-
Tidskriftsartikel (refereegranskat)abstract
- We report a stereoinvertive deoxygenation of trans-3-arylglycidates as an alternative route to access thermodynamically less stable (Z)-cinnamate esters by using nickel triflate and triphenylphosphine. Broad functional-group tolerance was observed, with trans-3-arylglycidates containing methyl, methoxy, halo, or nitro groups affording the corresponding (Z)-cinnamate esters in high yields and with moderate to high E/Z ratios.
|
|
| 6. |
- Akkarasamiyo, Sunisa, et al.
(författare)
-
Transition-Metal-Catalyzed Suzuki-Miyaura-Type Cross-Coupling Reactions of π-Activated Alcohols
- 2020
-
Ingår i: Synthesis (Stuttgart). - : Georg Thieme Verlag KG. - 0039-7881 .- 1437-210X. ; 52:5, s. 645-659
-
Forskningsöversikt (refereegranskat)abstract
- The Suzuki-Miyaura reaction is one of the most powerful tools for the formation of carbon-carbon bonds in organic synthesis. The utilization of alcohols in this powerful reaction is a challenging task. This short review covers progress in the transition-metal-catalyzed Suzuki--Miyaura-type cross-coupling reaction of pi-activated alcohol, such as aryl, benzylic, allylic, propargylic and allenic alcohols, between 2000 and June 2019.
|
|
| 7. |
- Akkarasamiyo, Sunisa, et al.
(författare)
-
Tsuji-Trost Reaction of Non-Derivatized Allylic Alcohols
- 2018
-
Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 24:14, s. 3488-3498
-
Tidskriftsartikel (refereegranskat)abstract
- Palladium-catalyzed allylic substitution of non-derivatized enantioenriched allylic alcohols with a variety of uncharged N-, S-, C- and O-centered nucleophiles using a bidentate BiPhePhos ligand is described. A remarkable effect of the counter ion (X) of the XPd[kappa(2)-BiPhePhos][kappa(3)-C3H5] was observed. When ClPd[kappa(2)-BiPhePhos][eta(3)-C3H5] (complexI) was used as catalyst, non-reproducible results were obtained. Study of the complex by X-ray crystallography, (PNMR)-P-31 spectroscopy, and ESI-MS showed that a decomposition occurred where one of the phosphite ligands was oxidized to the corresponding phosphate, generating ClPd[kappa(1)-BiPhePhosphite-phosphate][eta(3)-C3H5] species (complexII). When the chloride was exchanged to the weaker coordinating OTf- counter ion the more stable Pd[kappa(2)-BiPhePhos][eta(3)-C3H5](+)+[OTf] (-) (complexIII) was formed. ComplexIII performed better and gave higher enantiospecificities in the substitution reactions. ComplexIII was evaluated in Tsuji-Trost reactions of stereogenic non-derivatized allylic alcohols. The desired products were obtained in good to excellent yields (71-98%) and enantiospecificities (73-99%) for both inter- and intramolecular substitution reactions with only water generated as a by-product. The methodology was applied to key steps in total synthesis of (S)-cuspareine and (+)-lentiginosine. A reaction mechanism involving a palladium hydride as a key intermediate in the activation of the hydroxyl group is proposed in the overall transformation.
|
|
| 8. |
- Chitsomkhuan, Saranya, et al.
(författare)
-
Copper(II) Triflate Catalyzed Rearrangement of Amino 2,3-Epoxides to α-Amino Ketones
- 2024
-
Ingår i: Synlett. - 0936-5214 .- 1437-2096.
-
Tidskriftsartikel (refereegranskat)abstract
- α-Amino ketones were synthesized by a Meinwald rearrangement of biomass-based amino epoxides using copper(II) triflate as a catalyst. The regioselectivity of the rearrangement can be rationalized in terms of the reaction proceeding via the most stable carbocationic intermediate to give various α-amino α′-aryl ketones in moderate to good yields. This is an attractive method to prepare α-amino ketones using a benign and inexpensive catalyst.
|
|
| 9. |
- Gupta, Arvind Kumar, et al.
(författare)
-
Rich Coordination Chemistry of pi-Acceptor Dibenzoarsole Ligands
- 2017
-
Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 56:8, s. 4504-4511
-
Tidskriftsartikel (refereegranskat)abstract
- A series of dibenzoarsole (also known as 9-arsafluorene) derivatives have been prepared, and their coordination chemistry has been investigated. The different ligand topology and the arsenic substituents govern the reactivity of the ligands. We report various crystal structures of palladium and platinum complexes derived from this family of ligands. The biphenyl backbone of the bridged bidentate ligands allows very flexible coordination. We have also studied the application of an allylic Pd complex in nucleophilic substitution reactions, revealing that the benzoarsole substituent is susceptible to metal insertion.
|
|
| 10. |
- Rukkijakan, Thanya, et al.
(författare)
-
Pd-Catalyzed Substitution of the OH Group of Nonderivatized Allylic Alcohols by Phenols
- 2018
-
Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 83:7, s. 4099-4104
-
Tidskriftsartikel (refereegranskat)abstract
- Nonactivated phenols have been employed as nucleophiles in the allylation of nonderivatized allylic alcohols to generate allylated phenolic ethers with water as the only byproduct. A Pd[BiPhePhos] catalyst was found to be reactive to give the O-allylated phenols in good to excellent yields in the presence of molecular sieves. The reactions are chemo-selective in which the kinetically favored O-allylated products are formed exclusively over the thermodynamically favored C-allylated products.
|
|
