Synthesis and Reactivity of Binaphtholate Complexes of a d3-d3 Ditungsten Template

Steven D. Dietz; Nancy W. Eilerts; Joseph A. Heppert; David Vander Velde

doi:10.1021/ic00061a026

Synthesis and Reactivity of Binaphtholate Complexes of a d³-d³ Ditungsten Template

Steven D. Dietz, Nancy W. Eilerts, Joseph A. Heppert, David Vander Velde

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Abstract

W₂(O-t-Bu)₆ reacts with binaphthol derivatives (H₂BINO, R = H (1); H₂Me₂BINO, R = CH₃ (2)) to produce monosubstituted products of the formula (R₂BINO) W₂(O-t-Bu)₄. The presence of a single product in the ¹H NMR spectra of these compounds supports the hypothesis that the binaphtholate ligand adopts a preferential mode of binding. Disubstituted products can be formed when 2 equiv of binaphthol is reacted with W₂(O-t-Bu)₆: racemic binaphthol generates anti-(R,S)-(BINO)₂W₂(O-t-Bu)₂ (3) with small quantities of anfi-(R*,R*)-(BINO)₂W₂(O-t-Bu)₂ (5), while optically pure (R)-binaphthol yields gauche-(R,R)-(BINO)₂W₂(O-t-Bu)₂ (6). The enantiomers of 6 appear to undergo intermolecular exchange reactions in the presence of tert-butyl alcohol, forming 3 as the main product along with small quantities of (R*,R*,R*)-(BINO)₃W₂ (4). A reaction between 2 and 2 equiv of acetylene generates a flyover complex, (μ₂-C₄H₄)(Me₂BINO)W₂(O-t-Bu)₄ (7), as identified by ¹H and ¹³C NMR spectroscopy. When greater than 6 equiv of acetylene is employed, (η²-C₂H₂)(μ₂-C₄H₄)(Me₂BINO)₂W₂(O-t-Bu)₂ (8), a complex containing a flyover fragment with an additional terminal acetylene ligand, is produced. Complex 3 is also reactive toward acetylene, generating diastereomeric tris(acetylene) derivatives of the formula (μ₂-C₄H₄)-(η²-C₂H₂)(BINO)₂W₂(O-t-Bu)₂ (9) in a nonstatistical ratio. This result suggests that the presence of chiral chelating ligands in the coordination sphere can influence the stereochemistry of complex formation at the W₂ template.

Original language	English
Pages (from-to)	1689-1697
Number of pages	9
Journal	Inorganic Chemistry
Volume	32
Issue number	9
DOIs	https://doi.org/10.1021/ic00061a026
State	Published - 1993

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@article{0d64efbe719f43478b79986e90a61976,

title = "Synthesis and Reactivity of Binaphtholate Complexes of a d3-d3 Ditungsten Template",

abstract = "W2(O-t-Bu)6 reacts with binaphthol derivatives (H2BINO, R = H (1); H2Me2BINO, R = CH3 (2)) to produce monosubstituted products of the formula (R2BINO) W2(O-t-Bu)4. The presence of a single product in the 1H NMR spectra of these compounds supports the hypothesis that the binaphtholate ligand adopts a preferential mode of binding. Disubstituted products can be formed when 2 equiv of binaphthol is reacted with W2(O-t-Bu)6: racemic binaphthol generates anti-(R,S)-(BINO)2W2(O-t-Bu)2 (3) with small quantities of anfi-(R*,R*)-(BINO)2W2(O-t-Bu)2 (5), while optically pure (R)-binaphthol yields gauche-(R,R)-(BINO)2W2(O-t-Bu)2 (6). The enantiomers of 6 appear to undergo intermolecular exchange reactions in the presence of tert-butyl alcohol, forming 3 as the main product along with small quantities of (R*,R*,R*)-(BINO)3W2 (4). A reaction between 2 and 2 equiv of acetylene generates a flyover complex, (μ2-C4H4)(Me2BINO)W2(O-t-Bu)4 (7), as identified by 1H and 13C NMR spectroscopy. When greater than 6 equiv of acetylene is employed, (η2-C2H2)(μ2-C4H4)(Me2BINO)2W2(O-t-Bu)2 (8), a complex containing a flyover fragment with an additional terminal acetylene ligand, is produced. Complex 3 is also reactive toward acetylene, generating diastereomeric tris(acetylene) derivatives of the formula (μ2-C4H4)-(η2-C2H2)(BINO)2W2(O-t-Bu)2 (9) in a nonstatistical ratio. This result suggests that the presence of chiral chelating ligands in the coordination sphere can influence the stereochemistry of complex formation at the W2 template.",

author = "Dietz, {Steven D.} and Eilerts, {Nancy W.} and Heppert, {Joseph A.} and {Vander Velde}, David",

year = "1993",

doi = "10.1021/ic00061a026",

language = "English",

volume = "32",

pages = "1689--1697",

journal = "Inorganic Chemistry",

issn = "0020-1669",

publisher = "American Chemical Society",

number = "9",

}

TY - JOUR

T1 - Synthesis and Reactivity of Binaphtholate Complexes of a d3-d3 Ditungsten Template

AU - Dietz, Steven D.

AU - Eilerts, Nancy W.

AU - Heppert, Joseph A.

AU - Vander Velde, David

PY - 1993

Y1 - 1993

N2 - W2(O-t-Bu)6 reacts with binaphthol derivatives (H2BINO, R = H (1); H2Me2BINO, R = CH3 (2)) to produce monosubstituted products of the formula (R2BINO) W2(O-t-Bu)4. The presence of a single product in the 1H NMR spectra of these compounds supports the hypothesis that the binaphtholate ligand adopts a preferential mode of binding. Disubstituted products can be formed when 2 equiv of binaphthol is reacted with W2(O-t-Bu)6: racemic binaphthol generates anti-(R,S)-(BINO)2W2(O-t-Bu)2 (3) with small quantities of anfi-(R*,R*)-(BINO)2W2(O-t-Bu)2 (5), while optically pure (R)-binaphthol yields gauche-(R,R)-(BINO)2W2(O-t-Bu)2 (6). The enantiomers of 6 appear to undergo intermolecular exchange reactions in the presence of tert-butyl alcohol, forming 3 as the main product along with small quantities of (R*,R*,R*)-(BINO)3W2 (4). A reaction between 2 and 2 equiv of acetylene generates a flyover complex, (μ2-C4H4)(Me2BINO)W2(O-t-Bu)4 (7), as identified by 1H and 13C NMR spectroscopy. When greater than 6 equiv of acetylene is employed, (η2-C2H2)(μ2-C4H4)(Me2BINO)2W2(O-t-Bu)2 (8), a complex containing a flyover fragment with an additional terminal acetylene ligand, is produced. Complex 3 is also reactive toward acetylene, generating diastereomeric tris(acetylene) derivatives of the formula (μ2-C4H4)-(η2-C2H2)(BINO)2W2(O-t-Bu)2 (9) in a nonstatistical ratio. This result suggests that the presence of chiral chelating ligands in the coordination sphere can influence the stereochemistry of complex formation at the W2 template.

AB - W2(O-t-Bu)6 reacts with binaphthol derivatives (H2BINO, R = H (1); H2Me2BINO, R = CH3 (2)) to produce monosubstituted products of the formula (R2BINO) W2(O-t-Bu)4. The presence of a single product in the 1H NMR spectra of these compounds supports the hypothesis that the binaphtholate ligand adopts a preferential mode of binding. Disubstituted products can be formed when 2 equiv of binaphthol is reacted with W2(O-t-Bu)6: racemic binaphthol generates anti-(R,S)-(BINO)2W2(O-t-Bu)2 (3) with small quantities of anfi-(R*,R*)-(BINO)2W2(O-t-Bu)2 (5), while optically pure (R)-binaphthol yields gauche-(R,R)-(BINO)2W2(O-t-Bu)2 (6). The enantiomers of 6 appear to undergo intermolecular exchange reactions in the presence of tert-butyl alcohol, forming 3 as the main product along with small quantities of (R*,R*,R*)-(BINO)3W2 (4). A reaction between 2 and 2 equiv of acetylene generates a flyover complex, (μ2-C4H4)(Me2BINO)W2(O-t-Bu)4 (7), as identified by 1H and 13C NMR spectroscopy. When greater than 6 equiv of acetylene is employed, (η2-C2H2)(μ2-C4H4)(Me2BINO)2W2(O-t-Bu)2 (8), a complex containing a flyover fragment with an additional terminal acetylene ligand, is produced. Complex 3 is also reactive toward acetylene, generating diastereomeric tris(acetylene) derivatives of the formula (μ2-C4H4)-(η2-C2H2)(BINO)2W2(O-t-Bu)2 (9) in a nonstatistical ratio. This result suggests that the presence of chiral chelating ligands in the coordination sphere can influence the stereochemistry of complex formation at the W2 template.

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U2 - 10.1021/ic00061a026

DO - 10.1021/ic00061a026

M3 - Article

AN - SCOPUS:0040156726

SN - 0020-1669

VL - 32

SP - 1689

EP - 1697

JO - Inorganic Chemistry

JF - Inorganic Chemistry

IS - 9

ER -

Synthesis and Reactivity of Binaphtholate Complexes of a d³-d³ Ditungsten Template

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