X−H (X=C, N, O, P, S) Bond Activations Induced by -Heterosubstituted Zirconaindenes

Cadierno, Victorio; Zabłocka, Maria; Donnadieu, Bruno; Igau, Alain; Majoral, Jean‐Pierre; Skowronska, A.

doi:10.1002/1521-3765(20010105)7:1<221::aid-chem221>3.3.co;2-c

Cited by 16 publications

(25 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the s ‐ cis conformation can be destabilized by sterically demanding substituents. Other strategies are the incorporation of the phosphazide into a cyclic4 or macrocyclic5 system, or its coordination to metal atoms like boron,6 zirconium,7 molybdenum,8 tungsten,9 iron,10 ruthenium,11 cerium,12 or lutetium13 in which different coordination modes have been found. In a few cases, open‐chain phosphazides in an s ‐ cis conformation with CH 2 CN,14 adamantyl,15 or ortho ‐ closo ‐dicarbadodecaboranyl16 substituents at the γ‐nitrogen atom were observed.…”

Section: Introductionmentioning

confidence: 99%

Constrained‐Geometry Bisphosphazides Derived from 1,8‐Diazidonaphthalene: Synthesis, Spectroscopic Characteristics, Structural Features, and Theoretical Investigations

Kögel

Abacilar

Weber

et al. 2014

Chemistry A European J

View full text Add to dashboard Cite

Investigations on the Staudinger reaction between 1,8-diazidonaphthalene and phosphorous(III) building blocks, a key step in the synthesis of superbasic bisphosphazene proton sponges, yielded a set of bisphosphazides with a constrained geometry 1,8-disubstituted naphthalene backbone. This compound class has attracted our interest not only due to their surprisingly high stability, but in particular because of their theoretically predicted basicity in the range of their bisphosphazene analogues that can be referred to the constrained geometry interaction of two highly basic nitrogen atoms. Eleven new bisphosphazides bearing simple P-amino groups as well as P-guanidino substituents, azaphosphatrane moieties, P2 building blocks, or chiral P-amino substituents derived from L-proline are presented. They were studied concerning their spectroscopic properties and partly also their chromophoric and structural features. In the case of the pyrrolidino-substituted TPPN(2N2) (TPPN = 1,8-bis(trispyrrolidinophosphazenyl)naphthalene), the stepwise nitrogen elimination is investigated theoretically and experimentally, which led to the isolation and structural characterization of TPPN(1N2) bearing a phosphazide and a phosphazene functionality in one molecule. Attempts to protonate the obtained bisphosphazides and to prove the computationally predicted pKBH(+) values through NMR titration reactions resulted in their decay, which again was rationalized by theoretical calculations. Altogether we present the so far most extensive spectroscopic, structural and theoretical investigation of constrained geometry bisphosphazides and their Brønsted and Lewis basic properties.

show abstract

Section: Introductionmentioning

confidence: 99%

Constrained‐Geometry Bisphosphazides Derived from 1,8‐Diazidonaphthalene: Synthesis, Spectroscopic Characteristics, Structural Features, and Theoretical Investigations

Kögel

Abacilar

Weber

et al. 2014

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…In marked contrast, synthesis and properties of analogous systems containing both phosphorus and one additional heteroatom are quite undeveloped. Formal 1,2-addition of M-H or M-X reagents to the Zr-N intracyclic bond of 103 was observed, the manner of the addition varying dramatically from M-X to M-H species: metalation or phosphorylation at the imino nitrogen occurs when halogenated reagents are reacted with zirconaindenes, while protonation takes place with P-H spirophosphoranes, gold complexes, hydrogen chloride etc…(scheme 33) [34][35][36]. The transient benzynezirconocene complex was trapped by these cyanophosphines to give for example azazirconacyclopentenes 103a,b (scheme 31).…”

Section: Interactions Benzynezirconocene and Unsaturated Phosphines: mentioning

confidence: 99%

Synthesis of Phosphorus Ligands from Zirconium Reagents. A Useful Approach

Zabłocka¹,

Majoral

2007

COC

Self Cite

View full text Add to dashboard Cite

The use of several zirconium reagents as the Schwartz reagent [Cp 2 ZrHCl] n , the dimethylzirconocene Cp 2 ZrMe 2, the zirconocene [Cp 2 Zr], and the diphenylzirconocene Cp 2 ZrPh 2 allows the synthesis of a variety of new linear and cyclic P-C and P-N ligands. 1,1 diphosphines can be prepared from unsaturated monophosphines. A useful methodology involving ring opening reactions permits the preparation of phosphinite-phosphine and bis-phosphinite ligands. N-functionalized imines and -diimines substituted with phosphino groups are obtained from cyanophosphines or dinitriles. Carbozirconation of chlorophospha-imine leads to the unprecedented P-metalated iminophosphorane which presents a versatile reactivity towards electrophiles and small unsaturated molecules. Constraint three and four phosphorus cycles can be easily isolated using [Cp 2 M] (M = Zr or Ti). Interactions between benzynezirconocene and unsaturated phosphines afford numerous methods to prepare linear and cyclic phosphorus reagents. Enantiomerically pure iminophosphines can be synthetized from phosphinozirconocene complexes.

show abstract

“…[7] Indeed phosphanes 1 a and 1 b activate CÀH bonds in relatively acidic carbonic acids, such as acetylenes and methylene compounds. [8] Although electrophilic, metal-mediated, aliphatic C À H bond cleavage is precedented, [9] its application to the functionalization of complex substrates is very rare. The present report deals with a novel electrophilic sp 2 -CÀH bond activation and its application for the preparation of a-diazomethylzirconium complexes, which are the first C-metalated diazoalkanes L n MC(N 2 )R with an early transition metal.…”

mentioning

confidence: 99%

“…Selected bond lengths [] and angles[8]: Zr-O1 2.220(4), Zr-N1 2.258(4), Zr-C7 2.390(4), N1-C1 1.281(5), C1-P 1.861(4); O1-Zr-N1 70.89(12), N1-Zr-C7 67.71(13), Zr-O1-C8 146.1(2), Zr-N1-C1 126.1(3), Zr-C7-C2 116.3(3). Scheme 3.…”

mentioning

confidence: 99%