- Palladium-Catalyzed Reductive Carbonylation of (Hetero) Aryl Halides and Triflates Using Cobalt Carbonyl as CO Source
-
An efficient protocol for the reductive carbonylation of (hetero) aryl halides and triflates under CO gas-free conditions using Pd/Co2(CO)8 and triethylsilane has been developed. The mild reaction conditions, enhanced chemoselectivity and, easy access to heterocyclic and vinyl carboxaldehydes highlights its importance in organic synthesis.
- Dogga, Bhushanarao,Joseph, Jayan T.,Kumar, C. S. Ananda
-
supporting information
p. 309 - 313
(2020/12/23)
-
- Bismuth-Catalyzed Oxidative Coupling of Arylboronic Acids with Triflate and Nonaflate Salts
-
Herein we present a Bi-catalyzed cross-coupling of arylboronic acids with perfluoroalkyl sulfonate salts based on a Bi(III)/Bi(V) redox cycle. An electron-deficient sulfone ligand proved to be key for the successful implementation of this protocol, which allows the unusual construction of C(sp2)-O bonds using commercially available NaOTf and KONf as coupling partners. Preliminary mechanistic studies as well as theoretical investigations reveal the intermediacy of a highly electrophilic Bi(V) species, which rapidly eliminates phenyl triflate.
- Cornella, Josep,Peciukenas, Vytautas,Planas, Oriol
-
supporting information
p. 11382 - 11387
(2020/07/14)
-
- Palladium-Catalyzed Synthesis of N, N-Dimethylanilines via Buchwald-Hartwig Amination of (Hetero)aryl Triflates
-
This work delineates the synthesis of N,N-dimethylaniline derivatives from dimethylamines and aryl triflates. The palladium-catalyzed C-N bond formation proceeds in excellent yields, using an unsophisticated catalytic system, a mild base, and triflates as electrophiles, which are readily available from inexpensive phenols. N,N-Dimethylanilines are multifunctional reaction partners and represent useful but underutilized building blocks in organic synthesis.
- Pospech, Jola,Taeufer, Tobias
-
p. 7097 - 7111
(2020/06/27)
-
- Base-promoted selective O-phosphorylation of aryl triflates with P(O)-H compounds
-
Compared to previous transition metal-catalyzed C-phosphorylation reactions for constructing C–P bonds, in the absence of transition metal catalysts and ligands, a direct O-phosphorylation of aryl triflates selectively occurred with P(O)-H compounds in the presence of a base via the construction of O–P bonds. This transformation proceeds under simple and mild conditions, and provides a new method for the preparation of valuable organophosphoryl compounds from readily available P(O)-H compounds and triflates.
- Wang, Mingyue,Yang, Jia,Wang, Shuai,Zhong, Hong
-
supporting information
(2020/05/05)
-
- Catalytic Geminal Difluorination of Styrenes for the Construction of Fluorine-rich Bioisosteres
-
A geminal difluorination of alkenes based on I(I)/I(III) catalysis is disclosed, which is compatible with a range of electronically and substitutionally diverse styrenes (27 examples, up to 89% yield). Employing inexpensive p-TolI as the organocatalyst, turnover is enabled by Selectfluor-mediated oxidation to generate the ArIF2 species in situ. Extension to include α-substituted styrenes bearing fluorine-containing groups is disclosed and provides an expansive platform for the generation of fluorine-rich architectures.
- Scheidt, Felix,Neufeld, Jessica,Sch?fer, Michael,Thiehoff, Christian,Gilmour, Ryan
-
supporting information
p. 8073 - 8076
(2019/01/04)
-
- Remote migratory cross-electrophile coupling and olefin hydroarylation reactions enabled by in situ generation of nih
-
A highly efficient strategy for remote reductive cross-electrophile coupling has been developed through the ligand-controlled nickel migration/arylation. This general protocol allows the use of abundant and bench-stable alkyl bromides and aryl bromides for the synthesis of a wide range of structurally diverse 1, 1-diarylalkanes in excellent yields and high regioselectivities under mild conditions. We also demonstrated that alkyl bromide could be replaced by the proposed olefin intermediate while using n-propyl bromide/Mn0 as a potential hydride source.
- Chen, Fenglin,Chen, Ke,Zhang, Yao,He, Yuli,Wang, Yi-Ming,Zhu, Shaolin
-
supporting information
p. 13929 - 13935
(2017/11/07)
-
- Rapid Room-Temperature, Chemoselective Csp2?Csp2Coupling of Poly(pseudo)halogenated Arenes Enabled by Palladium(I) Catalysis in Air
-
While chemoselectivities in Pd0-catalyzed coupling reactions are frequently non-intuitive and a result of a complex interplay of ligand/catalyst, substrate, and reaction conditions, we herein report a general method based on PdIthat allows for an a priori predictable chemoselective Csp2?C Csp2coupling at C?Br in preference to C?OTf and C?Cl bonds, regardless of the electronic or steric bias of the substrate. The C?C bond formations are extremely rapid (Idimer under open-flask conditions.
- Kalvet, Indrek,Magnin, Guillaume,Schoenebeck, Franziska
-
supporting information
p. 1581 - 1585
(2017/02/05)
-
- Ligand- and Solvent-Tuned Chemoselective Carbonylation of Bromoaryl Triflates
-
The palladium-catalyzed chemoselective carbonylation of bromoaryl triflates is reported. The selective C?Br bond versus C?OTf (OTf=triflate) bond functionalization can be remarkably tuned by the combination of the ligand [4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) vs. 1,1′-bis(diphenylphosphino)ferrocene (DPPF)] and the solvent (toluene vs. DMSO). The respective ligand and solvent effects are rationalized by DFT calculations. In contrast, the monodentate ligands BuPAd2 and tBu3P prefer the selective C?Br bond activation and are solvent insensitive.
- Shen, Chaoren,Wei, Zhihong,Jiao, Haijun,Wu, Xiao-Feng
-
supporting information
p. 13369 - 1337
(2017/09/06)
-
- Reactions of triflate esters and triflamides with an organic neutral super-electron-donor
-
The bis-pyridinylidene 13 converts aliphatic and aryl triflate esters to the corresponding alcohols and phenols respectively, using DMF as solvent, generally in excellent yields. While the deprotection of aryl triflates has been seen with other reagents and by more than one mechanism, the deprotection of alkyl triflates is a new reaction. Studies with 18O labelled DMF indicate that the C-O bond stays intact and hence it is the S-O bond that cleaves, underlining that the cleavage results from the extraordinary electron donor capability of 13. Trifluoromethanesulfonamides are converted to the parent amines in like manner, representing the first cleavage of such substrates by a ground-state organic reducing reagent.
- Jolly, Phillip I.,Fleary-Roberts, Nadia,O'Sullivan, Steven,Doni, Eswararao,Zhou, Shengze,Murphy, John A.
-
supporting information; experimental part
p. 5807 - 5810
(2012/08/28)
-
- Zinc chloride-promoted aryl bromide-alkyne cross-coupling reactions at room temperature
-
(Chemical Equation Presented) Substoichiometric amounts of ZnCl2 promote the room temperature, Pd/P(t-Bu)3-catalyzed cross-coupling of aryl bromides with alkynes. Pd(I) dimer 1 is demonstrated to be a particularly active precatalyst for this reaction. The reaction is general for a wide variety of aryl bromides.
- Finke, Aaron D.,Elleby, Eric C.,Boyd, Michael J.,Weissman, Haim,Moore, Jeffrey S.
-
supporting information; experimental part
p. 8897 - 8900
(2010/03/01)
-
- Development of highly chemoselective bulky zincate complex, tBu 4ZnLi2: Design, structure, and practical applications in small-/macromolecular synthesis
-
We present full details of the unique reactivities of the newly developed dianion-type bulky zincate, dilithium tetra-ferf-butylzincate (tBu 4ZnLi2). With this reagent, halogen-zinc exchange reaction of variously functionalized haloaromatics and anionic polymerization of N-isopropylacrylamide (NIPAm)/styrene with excellent chemoselectivity were realized. Halogen-zinc exchange reaction followed by electrophilic trapping with propargyl bromide provided a convenient route to functionalized phenylallenes, particularly those with electrophilic functional groups (such as cyano, amide and halogens). Spectral and computational studies of the structure in the gas and liquid phases indicated extraordinary stabilization of this dianion-type zincate by its bulky ligands.
- Furayama, Taniyuki,Yonehara, Mitsuhiro,Arimoto, Sho,Kobayashi, Minoru,Matsumoto, Yotaro,Uchiyama, Masanobu
-
supporting information; experimental part
p. 10348 - 10356
(2009/10/10)
-
- Toward a protecting-group-free halogen-metal exchange reaction: Practical, chemoselective metalation of functionalized aromatic halides using dianion-type zincate,tBu4ZnLi2
-
A versatile preparation method for aromatic zincate compounds through a halogen-zinc exchange reaction using dilithium tetra-tert-butylzincate (tBu4ZnLi2) has been developed. This reagent permits efficient preparation of highly functionalized aromatic zincates, particularly, those with electrophilic functional groups, such as ester, amide, alcohol, and phenol. Halogen-zinc exchange reactions followed by electrophilic trapping (with allyl bromide or benzaldehyde) proved to be a powerful tool for C-C bond formation on functionalized aromatic rings. The functionalized aromatic zincate intermediate was also found to undergo copper- and palladium-catalyzed C-C bond-forming reactions with good yields and high chemoselectivity. Copyright
- Uchiyama, Masanobu,Furuyama, Taniyuki,Kobayashi, Minoru,Matsumoto, Yotaro,Tanaka, Kentaro
-
p. 8404 - 8405
(2007/10/03)
-
- A polystyrene-supported triflating reagent for the synthesis of aryl triflates
-
An insoluble polystyrene-supported triflating reagent has been prepared by suspension co-polymerization of N-(4-vinylphenyl)trifluoromethanesulphonimide, styrene and the JandaJel cross-linker. This reagent, in the presence of triethylamine, allows for the efficient synthesis of aryl triflates from a wide range of phenols in a process that permits the desired product to be isolated from the reaction mixture in essentially pure form via several filtration and concentration operations. Adding to the utility of this reagent is its ability to be easily recovered, regenerated and reused. Both soluble and insoluble bifunctional polymers containing trialkylamine moieties in addition to triflimide groups were also prepared and examined as triflating reagents. Unfortunately these reagents afforded only modest yields of the desired products in representative reactions. Graphical Abstract.
- Chung, Cecilia Wan Ying,Toy, Patrick H.
-
p. 709 - 715
(2007/10/03)
-
- A complementary method to obtain N-acyl enamides using the Heck reaction: Extending the substrate scope for asymmetric hydrogenation
-
A series of N-acyl enamides were prepared using the Heck reaction. Asymmetric hydrogenation provided protected amines in up to 99% ee. A method to prepare N-acyl enamides is reported that is complementary to the existing protocols. Heck reaction of a vari
- Harrison, Paul,Meek, Graham
-
p. 9277 - 9280
(2007/10/03)
-
- Practical Synthesis of Aryl Triflates under Aqueous Conditions
-
A practical and efficient synthesis of aryl triflates under biphasic basic aqueous conditions is described. The current methodology provides entry into these valuable substrates that omits the use of amine bases and allows facile isolation by s
- Frantz, Doug E.,Weaver, Damian G.,Carey, James P.,Kress, Michael H.,Dolling, Ulf H.
-
p. 4717 - 4718
(2007/10/03)
-
- Palladium Catalysed Alkoxycarbonylation of Phenols to Benzoate Esters
-
The methoxycarbonylation of aryl trifluoromethanesulphonates with CO and aliphatic alcohols is catalysed by Pd(OAc)2-1,3-bis(diphenylphosphino)propane in high yield at 70 deg C and ambient CO pressure.
- Dolle, Roland E.,Schmidt, Stanley J.,Kruse, Lawrence I.
-
p. 904 - 905
(2007/10/02)
-