Ytterbium trifluoromethanesulfonate [Yb(OTf)3] as a novel catalyst for the allylation of aldehydes

Aspinall, Helen C.; Browning, Andrew F.; Greeves, Nick; Ravenscroft, P.

doi:10.1016/s0040-4039(00)60750-5

Cited by 63 publications

(12 citation statements)

References 7 publications

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“…Indeed, such Lewis acids are effective catalysts in many fundamental processes, including acetalisation, 13,14 acylations, 15 Diels-Alder reactions, 16 Michael additions 17 and Friedel-Crafts reactions. 18 They have also been used to catalyse the addition of allylstannanes (both tetraallylstannane 19 and the less reactive allyltributylstannane 20 ) and tetraallylgermane 21 to carbonyl compounds. However, no reports on the addition of the much less reactive allylsilanes to aldehydes had been reported using catalytic quantities of transition metals.…”

mentioning

confidence: 99%

Sc(OTf)3, an Efficient Catalyst for Addition of Allyltrimethylsilane to Aldehydes; Chemoselective Addition to Aldehydes in Presence of Ketones and in situ Acylation (3 Component Coupling)

Aggarwal¹,

Vennall²

1998

Synthesis

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Scandium triflate (2-10 mol%) has been found to be a highly efficient catalyst for the addition of allyltrimethylsilane to both activated aromatic and aliphatic aldehydes. However, deactivated (electron rich) aromatic aldehydes gave double allylated products instead. Using a stoichiometric amount of Ac 2 O in the allylation reaction led directly to homoallylic acetates [in situ acylation catalysed by Sc(OTf) 3 ] and for the first time gave high yields of adducts with moderately electron rich aromatic aldehydes.The addition of allylsilanes to aldehydes catalysed by Lewis acids is an important synthetic transformation. 1-5 However, generally, tight binding of the product homoallylic alcohol to the Lewis acid catalyst, together with the poor efficiency of silicon transfer to oxygen results in poor turnover, thereby necessitating the use of stoichiometric (or greater) amounts of Lewis acid. 6 In the arena of asymmetric addition of allylsilanes to aldehydes chiral boron-based 7 and titanium-based Lewis acids 8 have been reported which (unusually) give good yields even when using only sub-stoichiometric amounts. Other notable catalysts for the allylation reaction using allyltrimethylsilane that have been used in sub-stoichiometric amounts are Brønsted acids [TfOH 2 + B(OTf) 4 -, 9 HN(SO 2 F) 2 ] 10 and super acids [Me 3 SiB(OTf) 4 ]. 11Unlike traditional Lewis acids (e.g. TiCl 4 , AlCl 3 , BF 3 • OEt 2 ), lanthanide and group III metal salts are known to form strong but labile bonds with oxygen-donor ligands. 12 This feature has often allowed sub-stoichiometric amounts of the Lewis acid to be used to promote a variety of reactions. Indeed, such Lewis acids are effective catalysts in many fundamental processes, including acetalisation, 13,14 acylations, 15 Diels-Alder reactions, 16 Michael additions 17 and Friedel-Crafts reactions. 18 They have also been used to catalyse the addition of allylstannanes (both tetraallylstannane 19 and the less reactive allyltributylstannane 20 ) and tetraallylgermane 21 to carbonyl compounds. However, no reports on the addition of the much less reactive allylsilanes to aldehydes had been reported using catalytic quantities of transition metals. In this paper we describe our studies in carbonyl allylation. 22The successful application of lanthanide and group III metal triflates to the reactions described above led us to screen a range of such catalysts in the reaction between allyltrimethylsilane and benzaldehyde in a range of solvents. After testing many solvent and catalyst combinations, it was found that Sc(OTf) 3 in nitromethane was an

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confidence: 99%

Sc(OTf)3, an Efficient Catalyst for Addition of Allyltrimethylsilane to Aldehydes; Chemoselective Addition to Aldehydes in Presence of Ketones and in situ Acylation (3 Component Coupling)

Aggarwal¹,

Vennall²

1998

Synthesis

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“…Since drying hydrated salts is not efficient, simple preparations of these anhydrous lanthanide salts have been developed. [315][316][317][318] Various strategies have been introduced to enhance the activity and facilitate recovery of these rare earth catalysts. 319 For example, immobilisation of lanthanide salts onto a mesoporous silicate provides an efficient heterogeneous catalysts for heteroatom Diels-Alder reactions with no leaching being observed, even after 6 cycles.…”

Section: Lanthanide(iii) Mediated Transformationsmentioning

confidence: 99%

Recent developments in lanthanide mediated organic synthesis

Steel

2001

J. Chem. Soc., Perkin Trans. 1

247

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“…The latter reaction is performed with allyl tributyltin in CHzClz (Eq. 16) [25]. Evidently the lanthanide triflate is only weakly bound to the alkoxide oxygen of the product enabling protonolysis to occur in the former case with protic solvents or cosolvents.…”

Section: Lewis Acid Catalysis Of Allyltin Additionsmentioning

confidence: 99%

Preparation and Addition Reactions of Allylic and Allenic Tin and Indium Reagents

Marshall¹

2000

Lewis Acids in Organic Synthesis

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Ytterbium trifluoromethanesulfonate [Yb(OTf)3] as a novel catalyst for the allylation of aldehydes

Cited by 63 publications

References 7 publications

Sc(OTf)3, an Efficient Catalyst for Addition of Allyltrimethylsilane to Aldehydes; Chemoselective Addition to Aldehydes in Presence of Ketones and in situ Acylation (3 Component Coupling)

Sc(OTf)3, an Efficient Catalyst for Addition of Allyltrimethylsilane to Aldehydes; Chemoselective Addition to Aldehydes in Presence of Ketones and in situ Acylation (3 Component Coupling)

Recent developments in lanthanide mediated organic synthesis

Preparation and Addition Reactions of Allylic and Allenic Tin and Indium Reagents

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