Dimeric P 5 -deltacyclene complexes: Variation of bridging modes and intact or partially opened P C cage ligand structures

Keller, Irene C.; Rohwer, Lars; Heinemann, Frank W.; Höhn, Christine; Zenneck, Ulrich

doi:10.1016/j.jorganchem.2016.04.023

Cited by 3 publications

(3 citation statements)

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“…Cs 2 CO 3 as the optimal reagent for the benzylation of 5 does not only cause the formation of known cage rearrangement products, but also novel ones. The cage rearrangement reactions of 5 are controlled by the specific reaction conditions including the chemical nature of the base and the solvent …”

Section: Discussionmentioning

confidence: 99%

“…Cs 2 CO 3 (140 mg, 0.43 mmol) was added after 3 h and the suspension was stirred for another 115 h. The deep orange reaction mixture was filtered and the solvent removed in vacuo. 31 P{ 1 H} NMR oft the raw product revealed 14 % unreacted starting material 5 , 28 mol‐% of the target product 10 , and variable amounts of known, and new cage rearrangement products of 5 . Column chromatography at water deactivated silica (6 % H 2 O) with n ‐hexane/EtOAc 40:1 led to pure 10 (108 mg, 0.21 mmol, 25 %) as a yellow solid.…”

Section: Methodsmentioning

confidence: 99%

“…Bases deprotonate the P‐H function of 5 . In the absence of suitable metals, which might stabilize the phosphidic center, deprotonated [ 5 – H] – rearranges rapidly to form cage inversion product iso‐P 5 ‐deltacyclene 8 after reprotonation . (Scheme )…”

Section: Introductionmentioning

confidence: 99%

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Stereoselective P₅-Deltacyclene Alkylation, an Efficient Route to New Asymmetric P-C-Cage Compounds

Keller

Höhn

Rohwer

et al. 2017

Z. Anorg. Allg. Chem.

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Tetra-tert-butyl-P 5 -deltacyclene 5 represents one of only two asymmetric P-C cage compounds, which are available in highly enantiomerically enriched versions. This paper reports about stereoselective substitution reactions of 5 to develop the chemistry of optically active P-C cages further. Electrophilic substitution of the only secondary phosphorus atom P1 of the cage with methyl and benzyl groups was achieved with 92 % and Ͼ99 % de, but the yields of the reactions are limited due to competing processes. The uncatalyzed hydrophosphination reaction of a monosubstituted allene and two α,β-unsaturated 922 carbonyl compounds with 5 proved to be the method of choice. cis-Butanone-P 5 -deltacyclene 12 is formed in 92 % yield and with Ͼ99 % de and cis-pentanone-P 5 -deltacyclene 13a is accessible with Ͼ99 % de for P1 and 92 % de for the attached carbon atom at the same time. Besides stereoselectivity, the hydrophosphination reaction of 5 performs with a good regioselectivity. The chiral cage 5 controls the stereoselectivity of its reactions for the cage elements as well as for the α position of a substituent.A novel aspect of this field of chemistry are optically active derivatives of chiral P-C cage compounds. [6][7][8] As a specific property of the derivatives of 3, a once established enantiomeric excess remains untouched by all reactions tested to date which do not disintegrate the molecules such as destannylation, [6] protonation, [7] deprotonation, [9] complexation, [7,9] oxidation, [10] and cage rearrangement including cage inversion. [9] In spite of its five P-lone pairs and a dynamic equilibrium between two epimers, P-H P 5 -deltacyclene 5 (Scheme 1) proved to be a highly selective ligand with metals of interest for catalytic applications. It forms only one single complex species in high yield for each of its enantiomers with the (benzene)Ru II Cl 2 fragment, for example. [7] Scheme 1. Preparation of P-H P 5 -deltacyclene 5 and iso-P 5 -deltacyclene 8. Journal of Inorganic and General ChemistryZeitschrift für anorganische und allgemeine Chemie ARTICLE ated [5 -H] -. [7,9] P-alkylation of a P-C cage compound has been reported for the first time for tetraphosphacubane (1), [11] and an asymmetric P-C cage has been used as well. [12] Cationic mono organylation and alkynylation products [1R] + are accessible with suitable electrophiles. 5 should form the cation [5R] + if treated in the same way as 1. A successive deprotonation of [5R] + with bases seemed to be possible and would lead to alkylated neutral cages, whose ligand properties with respect to metal cations would not be hampered by a positive charge. In spite of the bulkiness of the tetra-tert-butyl-P 5 -deltacyclene cage, the P-H function of 5 might be active as a hydrophosphination agent towards activated unsaturated organic compounds and form neutral alkyl-tetra-tert-butyl-P 5 -deltacyclene derivatives directly. In the case of prochiral organic substrates, the stereochemical aspects of the reaction are of interest for the potential use of the cages as ch...

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Stereoselective P₅-Deltacyclene Alkylation, an Efficient Route to New Asymmetric P-C-Cage Compounds

Keller

Höhn

Rohwer

et al. 2017

Z. Anorg. Allg. Chem.

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Three-Membered Rings With Two Heteroatoms Including Phosphorus to Bismuth

Damljanović¹,

Stevanović²

2022

Comprehensive Heterocyclic Chemistry IV

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Main group element-mediated phosphaalkyne by combined insertion and oligomerization reactions

Bani‐Fwaz

2020

Journal of Coordination Chemistry

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Dimeric P 5 -deltacyclene complexes: Variation of bridging modes and intact or partially opened P C cage ligand structures

Cited by 3 publications

References 76 publications

Stereoselective P₅-Deltacyclene Alkylation, an Efficient Route to New Asymmetric P-C-Cage Compounds

Stereoselective P₅-Deltacyclene Alkylation, an Efficient Route to New Asymmetric P-C-Cage Compounds

Three-Membered Rings With Two Heteroatoms Including Phosphorus to Bismuth

Main group element-mediated phosphaalkyne by combined insertion and oligomerization reactions

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Dimeric P 5 -deltacyclene complexes: Variation of bridging modes and intact or partially opened P C cage ligand structures

Cited by 3 publications

References 76 publications

Stereoselective P5-Deltacyclene Alkylation, an Efficient Route to New Asymmetric P-C-Cage Compounds

Stereoselective P5-Deltacyclene Alkylation, an Efficient Route to New Asymmetric P-C-Cage Compounds

Three-Membered Rings With Two Heteroatoms Including Phosphorus to Bismuth

Main group element-mediated phosphaalkyne by combined insertion and oligomerization reactions

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Stereoselective P₅-Deltacyclene Alkylation, an Efficient Route to New Asymmetric P-C-Cage Compounds

Stereoselective P₅-Deltacyclene Alkylation, an Efficient Route to New Asymmetric P-C-Cage Compounds