Diastereoselective Pd/In bimetallic inter–intramolecular (class 2) cascade reactions of allenyl-imines and aryl iodides

Cooper, Ian; Grigg, Ronald; Hardie, Michaele J.; MacLachlan, William S.; Sridharan, Visuvanathar; Thomas, W. A.

doi:10.1016/s0040-4039(03)00277-6

Cited by 32 publications

(15 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The transition metal‐catalyzed allylation of aldehydes and imines has attracted considerable attention due to the synthetic utility of corresponding homoallylic alcohol and amine products as well as the interesting reactivity of the allyl‐transition metal complex during the reaction 1,2,3,4. To accomplish such allylations using a catalytic amount of transition metal complexes and allylic acetates or allenes as starting materials, a range of protocols utilizing stoichiometric amounts of organometallic reagents (tin,2a,b,d,e,3c zinc,2c,h,i,j,m,p indium,2f,3a,b borane,2o,s,t,u and silane2k,q,r) which reverse the reactivity of the allyl‐metal complexes from electrophilic to nucleophilic have been investigated. Recently, the reactions of nucleophilic allyl‐iridium complexes were reported under transfer hydrogenation conditions where the use of metallic reductants were avoided 5…”

Section: Optimization Of the Reductive Cyclization Of Allene‐aldehydementioning

confidence: 99%

Platinum(II)‐Catalyzed Allylation of CO and CN Bonds under Hydrogenation Conditions

et al. 2010

View full text Add to dashboard Cite

Abstract:The nucleophilic addition of allylplatinum to a range of electrophiles including carbonyls, oximes, and hydrazones was examined. Platinum(II) catalysts and allene substrates were subject to hydrogenation conditions to generate nucleophilic allylplatinum complexes without using a stoichiometric amount of toxic and sensitive organometallic reagents. The allylplatinum intermediates reacted with C=O and C=N bonds to produce the corresponding homoallylic alcohol and amine derivatives in good yield. The Pt-catalyzed allylation of C=N bonds is the first example performed under hydrogenation conditions. A reaction mechanism initiated with the hydrometalation of allenes by Pt À H species is proposed based on deuterium labeling studies.Keywords: allylation; cyclization; hydrazones; hydrogenation; platinumThe transition metal-catalyzed allylation of aldehydes and imines has attracted considerable attention due to the synthetic utility of corresponding homoallylic alcohol and amine products as well as the interesting reactivity of the allyl-transition metal complex during the reaction. [1,2,3,4] To accomplish such allylations using a catalytic amount of transition metal complexes and allylic acetates or allenes as starting materials, a range of protocols utilizing stoichiometric amounts of organometallic reagents (tin, [2a,b,d,e,3c] zinc, [2c,h,i,j,m,p] indium, [2f,3a,b] borane, [2o,s,t,u] and silane [2k,q,r] ) which reverse the reactivity of the allyl-metal complexes from electrophilic to nucleophilic have been investigated. Recently, the reactions of nucleophilic allyl-iridium complexes were reported under transfer hydrogenation conditions where the use of metallic reductants were avoided.[5]Our continuing effort to develop nucleophilic Pt complex-catalyzed reactions under environmentally benign conditions without the use of large amounts of organometallic reagents prompts us to examine the reaction conditions to form a nucleophilic allyl-platinum complex from allenes, Pt catalysts, and hydrogen. Similar to allyl-palladium complexes, allyl-platinum complexes have been applied to electrophilic catalytic reactions such as allylic alkylations but, to the best of our knowledge, there is no report of the reaction of nucleophilic allyl-platinum complexes.[6] Based on Ptcatalyzed hydrogenative coupling reactions using a range of p systems investigated by our group, [7] Pt À H species formed from the Pt complex and hydrogen react with the allene to form a nucleophilic allyl-platinum species. This paper reports the Pt-catalyzed hydrogen-mediated reductive cyclization of allene-carbonyls, allene-oximes and allene-hydrazones where nucleophilic allyl-platinum complexes were generated without large amounts of organometallic reagents. A remarkable aspect of this protocol is that Pt-catalyzed allylations of the ketone and carbon-nitrogen double bonds (e.g., allyl-oximes and allyl-hydrazones) were realized under hydrogenation conditions for the first time. [8,9] Table 1 summarizes the reaction optimization process. Compound...

show abstract

Section: Optimization Of the Reductive Cyclization Of Allene‐aldehydementioning

confidence: 99%

Platinum(II)‐Catalyzed Allylation of CO and CN Bonds under Hydrogenation Conditions

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The process outlined in Scheme 1 has proved to be very efficient and has been applied in stereoselective synthesis of amines 7 and both α− and β−aminoacids 8 . Recently we have shown that additives, such as secondary amines, CuI or ascorbic acid have a beneficial effect on cascades involving allene/ArX as allyl precursors by shortening the reaction time for some less reactive electrophilic multiple bonds and increasing the yields.…”

Section: Z Schemementioning

confidence: 99%

Reactive organoallyl species generated from aryl halides and allene: allylation of α,β-unsaturated aldehydes and cyclic ketones employing Pd/In transmetallation processes

et al. 2008

Self Cite

View full text Add to dashboard Cite

Published paperCleghorn, L.A.T., Grigg, R., Savic, V. and Simic, M. (2008) Reactive organoallyl species generated from aryl halides and allene: allylation of alpha,beta-unsaturated aldehydes and cyclic ketones employing Pd/In transmetallation processes, Tetrahedron, Volume 64 (37), 8731-8738. eprints@whiterose.ac.uk Graphical AbstractTo create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. Abstract -Allylation of α,β−unsaturated aldehydes and cyclic ketones promoted by Pd/In transmetallation processes have been studied. The unsaturated aldehydes underwent regioselective 1,2-addition to afford secondary homoally alcohols. The reactions have been performed using Pd(OAc) 2 /PPh 3 as catalytic system and metallic indium affording the products in good yields. The same transformation with unsaturated ketones proved to be less efficient, while saturated cyclic ketones delivered generally excellent yields in the presence of CuI. In these latter processes the presence of a distal heteroatom influences the reaction rate. Reactive Organoallyl Species Generated from

show abstract

“…Enyne and . Cycloisomerization reactions of N-sulfenyl imines that provide 3-aminopyrrolidine products have also been described (eq 27) [40]. The addition of indium metal is necessary to promote these reactions.…”

Section: Heterocycle Synthesis Via Cycloisomerization Reactionsmentioning

confidence: 99%

Recent Developments in Palladium-Catalyzed Heterocycle Synthesis and Functionalization

Wolfe¹,

Thomas²

2005

COC

View full text Add to dashboard Cite

Diastereoselective Pd/In bimetallic inter–intramolecular (class 2) cascade reactions of allenyl-imines and aryl iodides

Cited by 32 publications

References 8 publications

Platinum(II)‐Catalyzed Allylation of CO and CN Bonds under Hydrogenation Conditions

Platinum(II)‐Catalyzed Allylation of CO and CN Bonds under Hydrogenation Conditions

Reactive organoallyl species generated from aryl halides and allene: allylation of α,β-unsaturated aldehydes and cyclic ketones employing Pd/In transmetallation processes

Recent Developments in Palladium-Catalyzed Heterocycle Synthesis and Functionalization

Contact Info

Product

Resources

About