Functionalization of Alkynes Catalyzed by<i>t</i>‐Bu‐P4 Base

Imahori, Tatsushi; Hori, Chieko; Kondo, Yoshinori

doi:10.1002/adsc.200404076

Cited by 89 publications

(38 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the course of our recent studies on base-promoted transformations, [3] we became interested in the selective functionalization of silylated nucleophiles using catalytic tBu-P4 base as a promoter. [4] A novel catalytic activation of various O, N, and C nucleophile-silicon bonds using tBu-P4 base was investigated to perform nucleophilic reactions with various electrophiles (Figure 1).…”

mentioning

confidence: 99%

Catalytic Activation of Silylated Nucleophiles Using tBu‐P4 as a Base

et al. 2005

Self Cite

View full text Add to dashboard Cite

Trialkylsilyl groups play an important role as effective protecting groups in organic synthesis. Various O, N, and C nucleophilic sites can be protected by trialkylsilyl groups to control the selectivity of reactions. The nucleophilic attack of a fluoride anion on a silyl group is recognized as one of the most useful methods for desilylation. The activation of the nucleophile–silicon bond is important not only for desilylation but also for the generation of a reactive nucleophilic anion to achieve a new bond formation. The phosphazene bases developed by Schwesinger are known to be strong non‐metallic organic bases. Among them, the tBu‐P4 base has been used for various selective deprotonative transformations, although the ability of tBu‐P4 base to activate silylated nucleophiles has not yet been shown. A novel catalytic activation of various O, N, and C nucleophile–silicon bonds using tBu‐P4 base was investigated to perform nucleophilic reactions with various electrophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

show abstract

mentioning

confidence: 99%

Catalytic Activation of Silylated Nucleophiles Using tBu‐P4 as a Base

et al. 2005

Self Cite

View full text Add to dashboard Cite

show abstract

“…Flash chromatography (FC; cyclohexane) gave (P) 4 -(À)-4 a as a white solid (5 mg, 75 %). (10,11,22,23)), 78.29 (C (9,12,21,24)), 86.49 (C(4, 5, 16, 17)), 103.27 (C (1,8,13,20)), 104.56 (C (3,8,15,20)), 214.49 ppm (C(2, 7, 14, 19) 7,10,6,10,8, 2 -(+)-5 a): Acetone (0.660 mL, 0.525 mmol) was added to a solution of dimeric allene (P) 2 -(+)-9 (50 mg, 0.105 mmol) in Me 2 SO (1.1 mL), followed by the dropwise addition of with 1 m tBu-P4 base in hexane (30 mL). The mixture was stirred for 3 h at 25 8C, diluted with a saturated NH 4 Cl, and extracted with CHCl 3 (3 15 mL).…”

Section: -(à)-A)mentioning

confidence: 99%

Outstanding Chiroptical Properties: A Signature of Enantiomerically Pure Alleno–Acetylenic Macrocycles and Monodisperse Acyclic Oligomers

Donckèle

Gidron

Trapp

et al. 2014

Chemistry A European J

View full text Add to dashboard Cite

A second series of shape-persistent alleno-acetylenic macrocycles and monodisperse acyclic oligomers with conformationally less flexible backbones were synthesized in enantiomerically pure form by short, high-yielding routes starting from optically active 1,3-diethynylallenes. All seven stereoisomers-two pairs of enantiomers and three achiral stereoisomers-in the macrocyclic series were separated and configurationally assigned. The electronic circular dichroism (ECD) spectra of the D2 -symmetric, (P,P,P,P)- and (M,M,M,M)-configured macrocycles display remarkably intense chiroptical responses. A strong amplification of chirality is observed in the acyclic oligomeric series. Their preference for helical secondary structures of one handedness was supported by X-ray analysis and computational studies. This new set of data provides proof that outstanding ECD responses are a hallmark of alleno-acetylenic macrocyclic and acyclic oligomeric chromophores.

show abstract

“…Alkynes were easily transformed to enol ethers and enamines in dimethyl sulfoxide (DMSO) by the addition of nucleophiles. When phenylacetylene was reacted with diisopropylamine, a unique head-to-head dimerization of phenylacetylene was observed to give the enyne derivative [53] (Scheme 5.34).…”

Section: Addition Of Nucleophiles To Alkynementioning

confidence: 99%