Application of Dialkylaminosulfur Trifluorides in the Synthesis of Fluoroorganic Compounds

Markovskij, L. N.; Pashinnik, V. E.; Kirsanov, A. V.

doi:10.1055/s-1973-22302

Cited by 263 publications

(75 citation statements)

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“…Ar 4 SbF (10) is readily available by treatment of Ar 5 Sb (6) with diethylaminosulfur trifluoride (DAST) (Scheme 6). [25] This reaction is similar to the known halogenation of pentaarylantimony compounds by Cl 2 , Br 2 , or I 2 . [26] The arylation of 10 with TolMgBr proceeded smoothly to give Ar 4 TolSb (5) in good yield (Scheme 6).…”

Section: Resultssupporting

confidence: 62%

Syntheses, Crystal and Solution Structures, Ligand‐Exchange, and Ligand‐Coupling Reactions of Mixed Pentaarylantimony Compounds

Schröder

Okinaka

Mimura

et al. 2007

Chemistry A European J

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All possible combinations of mixed pentaarylantimony compounds bearing p-methylphenyl and p-trifluoromethylphenyl groups were synthesized; ArnTol5-nSb (n=0-5: Ar=p-CF3C6H4, Tol=p-CH3C6H4): Tol5Sb (1), ArTol4Sb (2), Ar2Tol3Sb (3), Ar3Tol2Sb (4), Ar4TolSb (5), and Ar5Sb (6). Compounds 2-5 are the first well-characterized examples of mixed acyclic pentaarylantimony species. The structures of 2-6 were determined by X-ray crystallography to feature trigonal-bipyramidal (TBP) geometry with the more electronegative p-trifluoromethylphenyl substituents selectively occupying the apical positions. Consideration of the chemical shifts of the ipso carbons of the aryl and tolyl groups suggested that the solution structures of 1-6 were also TBP, although their pseudorotation could not be frozen even at -80 degrees C. Ligand-exchange reactions (LERs) took place between 1 and 6 at approximately 60 degrees C in [D6]benzene and all six species 1-6 were found in the equilibrium mixture. The relative stabilities of 1-6 were determined quantitatively by comparison of the observed molar ratios of 1-6 in equilibrium with calculated statistical molar ratios, and Ar2Tol3Sb (3) was found to be the most stable. The ligand-coupling reactions (LCRs) of 2-5 in solution were greatly accelerated by adding Cu(acac)2 or Li+TFPB- (TFPB: [3,5-(CF3)2 C6H3]4 B), whereby the rate becomes comparable to the LER. The use of flash vacuum thermolysis (FVT) allowed the LCR to occur with very little ligand-exchange; the exception ArTol4Sb had very fast ligand-exchange. The selectivities of the LCRs were calculated from the yield of the biaryls synthesized by using FVT. These results were highly consistent with reactions catalyzed in solution, in which bitolyl was not obtained at all. The experimental results suggested that the LCR of pentaarylantimony compounds proceeds in the manner of apical-apical coupling.

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Section: Resultssupporting

confidence: 62%

Syntheses, Crystal and Solution Structures, Ligand‐Exchange, and Ligand‐Coupling Reactions of Mixed Pentaarylantimony Compounds

Schröder

Okinaka

Mimura

et al. 2007

Chemistry A European J

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“…Instead, difluoromethylarenes are typically accessed by deoxo gem-difluorination of the corresponding aldehydes with aminosulfurtrifluorides (DAST, Deoxofluor), BrF 3 Py or a combination of HF-pyridine and N-halo imide or amide [9][10][11][12] . Since these reactions were conducted under harsh reaction conditions and various functional groups were not compatible, many efforts have been made towards the development of alternative ways to introduce the difluoromethyl group into the desired position of the aromatic rings.…”

mentioning

confidence: 99%

Cooperative dual palladium/silver catalyst for direct difluoromethylation of aryl bromides and iodides

2014

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Difluoromethylated arenes are one of the privileged structural motifs that are important for fine tuning the biological properties of drug molecules. No general catalytic method exists for the formation of difluoromethylarenes. Previous methods for the preparation of difluoromethylarenes typically required harsh conditions, multiple steps or stoichiometric amount of catalysts. Here we report a cooperative dual palladium/silver catalyst system for direct difluoromethylation of aryl bromides and iodides under mild conditions. We develop the system by initial preparation of the putative intermediates in the dual-catalytic cycles, followed by studying the elemental steps to demonstrate the viability of the proposed cooperative catalytic cycle. The reaction is compatible with a variety of functional groups such as ester, amide, protected phenoxide, protected ketone, cyclopropyl, bromide and heteroaryl subunits such as pyrrole, benzothiazole, carbazole or pyridine.

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“…DAST reactions with carboxylic acids are known to give the corresponding acid fluorides [6,24] (the same is also expected in DAST reactions with anhydrides, since the HF generated in situ in DAST reactions catalyzes ring opening). Thus, as shown in Scheme 1, 7-hydroxydiacid 2 was first converted to the corresponding diester 3 via the Khurana procedure [25].…”

Section: Stereospecific Synthesis Of Anti-7-fluoronadic Dimethyl Estementioning

confidence: 58%

Stereospecific mono- and difluorination of the C7-bridge of norbornenes

Rajsfus

Alter-Zilberfarb

Sharon

et al. 2011

Journal of Fluorine Chemistry

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Application of Dialkylaminosulfur Trifluorides in the Synthesis of Fluoroorganic Compounds

Cited by 263 publications

References 0 publications

Syntheses, Crystal and Solution Structures, Ligand‐Exchange, and Ligand‐Coupling Reactions of Mixed Pentaarylantimony Compounds

Syntheses, Crystal and Solution Structures, Ligand‐Exchange, and Ligand‐Coupling Reactions of Mixed Pentaarylantimony Compounds

Cooperative dual palladium/silver catalyst for direct difluoromethylation of aryl bromides and iodides

Stereospecific mono- and difluorination of the C7-bridge of norbornenes

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