Comparative study of diastereoisomer interconversion in chiral BINOL-ate and diamine platinum complexes of conformationally flexible NUPHOS diphosphines

Simon Doherty; Colin R. Newman; Rakesh K. Rath; Jan Albert Van Den Berg; Christopher Hardacre; Mark Nieuwenhuyzen; Julian G. Knight

doi:10.1021/om034289f

Comparative study of diastereoisomer interconversion in chiral BINOL-ate and diamine platinum complexes of conformationally flexible NUPHOS diphosphines

Simon Doherty^*, Colin R. Newman, Rakesh K. Rath, Jan Albert Van Den Berg, Christopher Hardacre, Mark Nieuwenhuyzen, Julian G. Knight

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

A thorough and detailed study of diastereointerconversion in the chiral platinum complexes [(NUPHOS)Pt{(S)-BINOL}] (3a-e) has been undertaken and compared with the results of a similar study with [(BIPHEP)Pt{(S)-BINOL}]. Rate data revealed that this process obeys first-order relaxation kinetics, and rate constants for conversion of the minor to the major diastereoisomer have been obtained. Eyring analysis of the data gave ΔH^‡ and ΔS^‡ values of 22-25 kcal mol^-1 and -1 to -16 eu, respectively. In combination with computational analysis, these studies indicate that atropinversion most likely occurs via an on-metal pathway involving a planar seven-membered transition state. Substitution of (S)-BINOL for (S,S)-DPEN results in a marked reduction in the barrier to atropinversion; a ΔH^‡ value of 17 kcal mol^-1 has been determined for the conversion of δ-[(Ph₄-NUPHOS)Pt{(S,S)-DPEN}]-Cl₂ to λ-[(Ph₄-NUPHOS)Pt{(S,S)-DPEN}]Cl₂, which could indicate that an alternative mechanism operates.

Original language	English
Pages (from-to)	1055-1064
Number of pages	10
Journal	Organometallics
Volume	23
Issue number	5
DOIs	https://doi.org/10.1021/om034289f
Publication status	Published - 1 Mar 2004

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@article{97e33fa8471a46599f2b104627023f67,

title = "Comparative study of diastereoisomer interconversion in chiral BINOL-ate and diamine platinum complexes of conformationally flexible NUPHOS diphosphines",

abstract = "A thorough and detailed study of diastereointerconversion in the chiral platinum complexes [(NUPHOS)Pt{(S)-BINOL}] (3a-e) has been undertaken and compared with the results of a similar study with [(BIPHEP)Pt{(S)-BINOL}]. Rate data revealed that this process obeys first-order relaxation kinetics, and rate constants for conversion of the minor to the major diastereoisomer have been obtained. Eyring analysis of the data gave ΔH‡ and ΔS‡ values of 22-25 kcal mol-1 and -1 to -16 eu, respectively. In combination with computational analysis, these studies indicate that atropinversion most likely occurs via an on-metal pathway involving a planar seven-membered transition state. Substitution of (S)-BINOL for (S,S)-DPEN results in a marked reduction in the barrier to atropinversion; a ΔH‡ value of 17 kcal mol-1 has been determined for the conversion of δ-[(Ph4-NUPHOS)Pt{(S,S)-DPEN}]-Cl2 to λ-[(Ph4-NUPHOS)Pt{(S,S)-DPEN}]Cl2, which could indicate that an alternative mechanism operates.",

author = "Simon Doherty and Newman, {Colin R.} and Rath, {Rakesh K.} and {Van Den Berg}, {Jan Albert} and Christopher Hardacre and Mark Nieuwenhuyzen and Knight, {Julian G.}",

year = "2004",

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doi = "10.1021/om034289f",

language = "English",

volume = "23",

pages = "1055--1064",

journal = "Organometallics",

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publisher = "American Chemical Society",

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T1 - Comparative study of diastereoisomer interconversion in chiral BINOL-ate and diamine platinum complexes of conformationally flexible NUPHOS diphosphines

AU - Doherty, Simon

AU - Newman, Colin R.

AU - Rath, Rakesh K.

AU - Van Den Berg, Jan Albert

AU - Hardacre, Christopher

AU - Nieuwenhuyzen, Mark

AU - Knight, Julian G.

PY - 2004/3/1

Y1 - 2004/3/1

N2 - A thorough and detailed study of diastereointerconversion in the chiral platinum complexes [(NUPHOS)Pt{(S)-BINOL}] (3a-e) has been undertaken and compared with the results of a similar study with [(BIPHEP)Pt{(S)-BINOL}]. Rate data revealed that this process obeys first-order relaxation kinetics, and rate constants for conversion of the minor to the major diastereoisomer have been obtained. Eyring analysis of the data gave ΔH‡ and ΔS‡ values of 22-25 kcal mol-1 and -1 to -16 eu, respectively. In combination with computational analysis, these studies indicate that atropinversion most likely occurs via an on-metal pathway involving a planar seven-membered transition state. Substitution of (S)-BINOL for (S,S)-DPEN results in a marked reduction in the barrier to atropinversion; a ΔH‡ value of 17 kcal mol-1 has been determined for the conversion of δ-[(Ph4-NUPHOS)Pt{(S,S)-DPEN}]-Cl2 to λ-[(Ph4-NUPHOS)Pt{(S,S)-DPEN}]Cl2, which could indicate that an alternative mechanism operates.

AB - A thorough and detailed study of diastereointerconversion in the chiral platinum complexes [(NUPHOS)Pt{(S)-BINOL}] (3a-e) has been undertaken and compared with the results of a similar study with [(BIPHEP)Pt{(S)-BINOL}]. Rate data revealed that this process obeys first-order relaxation kinetics, and rate constants for conversion of the minor to the major diastereoisomer have been obtained. Eyring analysis of the data gave ΔH‡ and ΔS‡ values of 22-25 kcal mol-1 and -1 to -16 eu, respectively. In combination with computational analysis, these studies indicate that atropinversion most likely occurs via an on-metal pathway involving a planar seven-membered transition state. Substitution of (S)-BINOL for (S,S)-DPEN results in a marked reduction in the barrier to atropinversion; a ΔH‡ value of 17 kcal mol-1 has been determined for the conversion of δ-[(Ph4-NUPHOS)Pt{(S,S)-DPEN}]-Cl2 to λ-[(Ph4-NUPHOS)Pt{(S,S)-DPEN}]Cl2, which could indicate that an alternative mechanism operates.

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U2 - 10.1021/om034289f

DO - 10.1021/om034289f

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Comparative study of diastereoisomer interconversion in chiral BINOL-ate and diamine platinum complexes of conformationally flexible NUPHOS diphosphines

Abstract

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CCDC 238200: Experimental Crystal Structure Determination

CCDC 240058: Experimental Crystal Structure Determination

CCDC 238199: Experimental Crystal Structure Determination

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Comparative study of diastereoisomer interconversion in chiral BINOL-ate and diamine platinum complexes of conformationally flexible NUPHOS diphosphines

Abstract

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Datasets

CCDC 238200: Experimental Crystal Structure Determination

CCDC 240058: Experimental Crystal Structure Determination

CCDC 238199: Experimental Crystal Structure Determination

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