Alkaline earth catalysis of alkynyl alcohol hydroalkoxylation/cyclization

C. Brinkmann, A.G.M. Barrett, S. Reid, M.S. Hill, P.A. Procopiou

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Heavier alkaline earth bis(trimethylsilyl)amides [Ae{N(SiMe3)2}2]2 (Ae = Ca, Sr, Ba) are shown to act as effective precatalysts for the regioselective intramolecular hydroalkoxylation/cyclization of a wide range of alkynyl and allenyl alcohols. In the majority of cases, cyclization of alkynyl alcohols produces mixtures of the possible endo- and exocyclic enol ether products, rationalized as a consequence of alkynylalkoxide isomerization to the corresponding allene derivatives. Cyclization rates for terminal alkynyl alcohols were found to be significantly higher than for substrates bearing internal alkynyl substituents, while the efficacy of cyclization was in general found to be determined by a combination of stereoelectronic influences and the thermochemical viability of the specific alkaline earth metal catalysis, which we suggest is determined by the individual M–O bond strengths. Kinetic studies have provided a rate law pertaining to a pronounced catalyst inhibition with increasing [substrate], indicating that turnover-limiting insertion of C–C unsaturation into the M–O bond requires the dissociation of substrate molecules away from the Lewis acidic alkaline earth center.
Original languageEnglish
Pages (from-to)7287-7297
Number of pages11
JournalOrganometallics
Volume31
Issue number20
Early online date30 Sep 2012
DOIs
Publication statusPublished - 22 Oct 2012

Fingerprint

Cyclization
Catalysis
catalysis
alcohols
Earth (planet)
Alcohols
Bearings (structural)
Substrates
alkaline earth metals
Alkaline Earth Metals
viability
amides
isomerization
insertion
ethers
Isomerization
Amides
Ether
dissociation
catalysts

Cite this

Brinkmann, C., Barrett, A. G. M., Reid, S., Hill, M. S., & Procopiou, P. A. (2012). Alkaline earth catalysis of alkynyl alcohol hydroalkoxylation/cyclization. Organometallics, 31(20), 7287-7297. https://doi.org/10.1021/om3008663

Alkaline earth catalysis of alkynyl alcohol hydroalkoxylation/cyclization. / Brinkmann, C.; Barrett, A.G.M.; Reid, S.; Hill, M.S.; Procopiou, P.A.

In: Organometallics, Vol. 31, No. 20, 22.10.2012, p. 7287-7297.

Research output: Contribution to journalArticle

Brinkmann, C, Barrett, AGM, Reid, S, Hill, MS & Procopiou, PA 2012, 'Alkaline earth catalysis of alkynyl alcohol hydroalkoxylation/cyclization', Organometallics, vol. 31, no. 20, pp. 7287-7297. https://doi.org/10.1021/om3008663
Brinkmann, C. ; Barrett, A.G.M. ; Reid, S. ; Hill, M.S. ; Procopiou, P.A. / Alkaline earth catalysis of alkynyl alcohol hydroalkoxylation/cyclization. In: Organometallics. 2012 ; Vol. 31, No. 20. pp. 7287-7297.
@article{e1e1cd44ab174e2cab34523316d115c8,
title = "Alkaline earth catalysis of alkynyl alcohol hydroalkoxylation/cyclization",
abstract = "Heavier alkaline earth bis(trimethylsilyl)amides [Ae{N(SiMe3)2}2]2 (Ae = Ca, Sr, Ba) are shown to act as effective precatalysts for the regioselective intramolecular hydroalkoxylation/cyclization of a wide range of alkynyl and allenyl alcohols. In the majority of cases, cyclization of alkynyl alcohols produces mixtures of the possible endo- and exocyclic enol ether products, rationalized as a consequence of alkynylalkoxide isomerization to the corresponding allene derivatives. Cyclization rates for terminal alkynyl alcohols were found to be significantly higher than for substrates bearing internal alkynyl substituents, while the efficacy of cyclization was in general found to be determined by a combination of stereoelectronic influences and the thermochemical viability of the specific alkaline earth metal catalysis, which we suggest is determined by the individual M–O bond strengths. Kinetic studies have provided a rate law pertaining to a pronounced catalyst inhibition with increasing [substrate], indicating that turnover-limiting insertion of C–C unsaturation into the M–O bond requires the dissociation of substrate molecules away from the Lewis acidic alkaline earth center.",
author = "C. Brinkmann and A.G.M. Barrett and S. Reid and M.S. Hill and P.A. Procopiou",
year = "2012",
month = "10",
day = "22",
doi = "10.1021/om3008663",
language = "English",
volume = "31",
pages = "7287--7297",
journal = "Organometallics",
issn = "0276-7333",
publisher = "American Chemical Society",
number = "20",

}

TY - JOUR

T1 - Alkaline earth catalysis of alkynyl alcohol hydroalkoxylation/cyclization

AU - Brinkmann, C.

AU - Barrett, A.G.M.

AU - Reid, S.

AU - Hill, M.S.

AU - Procopiou, P.A.

PY - 2012/10/22

Y1 - 2012/10/22

N2 - Heavier alkaline earth bis(trimethylsilyl)amides [Ae{N(SiMe3)2}2]2 (Ae = Ca, Sr, Ba) are shown to act as effective precatalysts for the regioselective intramolecular hydroalkoxylation/cyclization of a wide range of alkynyl and allenyl alcohols. In the majority of cases, cyclization of alkynyl alcohols produces mixtures of the possible endo- and exocyclic enol ether products, rationalized as a consequence of alkynylalkoxide isomerization to the corresponding allene derivatives. Cyclization rates for terminal alkynyl alcohols were found to be significantly higher than for substrates bearing internal alkynyl substituents, while the efficacy of cyclization was in general found to be determined by a combination of stereoelectronic influences and the thermochemical viability of the specific alkaline earth metal catalysis, which we suggest is determined by the individual M–O bond strengths. Kinetic studies have provided a rate law pertaining to a pronounced catalyst inhibition with increasing [substrate], indicating that turnover-limiting insertion of C–C unsaturation into the M–O bond requires the dissociation of substrate molecules away from the Lewis acidic alkaline earth center.

AB - Heavier alkaline earth bis(trimethylsilyl)amides [Ae{N(SiMe3)2}2]2 (Ae = Ca, Sr, Ba) are shown to act as effective precatalysts for the regioselective intramolecular hydroalkoxylation/cyclization of a wide range of alkynyl and allenyl alcohols. In the majority of cases, cyclization of alkynyl alcohols produces mixtures of the possible endo- and exocyclic enol ether products, rationalized as a consequence of alkynylalkoxide isomerization to the corresponding allene derivatives. Cyclization rates for terminal alkynyl alcohols were found to be significantly higher than for substrates bearing internal alkynyl substituents, while the efficacy of cyclization was in general found to be determined by a combination of stereoelectronic influences and the thermochemical viability of the specific alkaline earth metal catalysis, which we suggest is determined by the individual M–O bond strengths. Kinetic studies have provided a rate law pertaining to a pronounced catalyst inhibition with increasing [substrate], indicating that turnover-limiting insertion of C–C unsaturation into the M–O bond requires the dissociation of substrate molecules away from the Lewis acidic alkaline earth center.

UR - http://www.scopus.com/inward/record.url?scp=84867754267&partnerID=8YFLogxK

UR - http://dx.doi.org/10.1021/om3008663

U2 - 10.1021/om3008663

DO - 10.1021/om3008663

M3 - Article

VL - 31

SP - 7287

EP - 7297

JO - Organometallics

JF - Organometallics

SN - 0276-7333

IS - 20

ER -