Scope of the directed dihydroxylation: application to cyclic homoallylic alcohols and trihaloacetamides

Donohoe, Timothy J.; Mitchell, Lee; Waring, Michael J.; Helliwell, Madeleine; Bell, Andrew S.; Newcombe, Nicholas J.

doi:10.1039/b303081d

Cited by 36 publications

(11 citation statements)

References 25 publications

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“…The first substrates investigated in this project were the cis ‐ and trans ‐cyclohexene derivatives 5 and 6 , which were prepared from the known diols 3 10 and 4 11 as shown in Scheme . The metathesis of these compounds could proceed in two ways: a simple RCM leading to 6,8‐fused bicyclic bis‐ethers 7 and 8 , or a RCM‐ROM‐RCM cascade involving the cyclohexene unit and leading to bis‐dihydropyrans 9 and 10 (Scheme ).…”

Section: Resultsmentioning

confidence: 99%

“…cis ‐1,2‐Bis(prop‐2‐ynyloxy)cyclohex‐4‐ene (35): To a stirring solution of cis ‐1,2‐dihydroxycyclohex‐4‐ene10 ( 3 , 0.9 g, 7.8 mmol) in DMF (20 mL) at 0 °C was slowly added NaH (60 % in mineral oil, 0.94 g, 23.5 mmol). After stirring for 1 h at 0 °C, propargyl bromide (80 % solution in toluene, 3.5 g, 2.6 mL, 23.5 mmol) was added and the reaction mixture was warmed to room temperature and stirred overnight.…”

Section: Methodsmentioning

confidence: 99%

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Synthesis of Cyclic and Macrocyclic Ethers Using Metathesis Reactions of Alkenes and Alkynes

Groaz¹,

Banti²,

North³

2007

Eur J Org Chem

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The metathesis transformations of cyclohexanes and cyclohexenes bearing allylic and/or propargylic ether substituents has been investigated. A range of products containing fused 6,8-bicyclic ring systems resulting from alkene and/or enyne metatheses were obtained using first and second generation, well defined alkylidene ruthenium catalysts. However, the unstrained cyclohexene unit did not participate in any of these metathesis processes, even though doing so would have led to a thermodynamically more stable product. This contrasts with previous results on similar compounds and on the corresponding amino-substituted cyclohexenes. The synthesis of dienes and dihydrofurans by metathesis processes involving the side chains of suitable cyclohexene ethers is

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Synthesis of Cyclic and Macrocyclic Ethers Using Metathesis Reactions of Alkenes and Alkynes

Groaz¹,

Banti²,

North³

2007

Eur J Org Chem

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“…1,6-Heptadiene was purchased and freezedried before use. 4-tert-Butyldimethylsiloxy-1,6-heptadiene, 24 4-triisopropylsiloxy-1,6-heptadiene, 24 4-phenyl-1,6-heptadiene 25 and 9,9-diallylfluorene 26 were synthesized according to the reported procedure.…”

Section: Experimental Materialsmentioning

confidence: 99%

Selective cyclopolymerization of α,ω-dienes and copolymerization with ethylene catalyzed by Fe and Co complexes

et al. 2009

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Fe complexes with bis(imino)pyridine ligands catalyze cyclopolymerization of 1,6-heptadiene in the presence of MMAO (modified methylalumoxiane) co-catalyst to produce the polymer containing five-membered rings in every repeating unit. The complexes with Me, Et, and Cl substituents at the N-aryl groups of the ligand produce the polymer in high yields and in high trans-cis ratio of the five-membered rings. The molecular weights of the polymers, M(n) by GPC, are higher than 6000. The polymerization promoted by the Fe complexes with bulky N-aryl groups of the ligand gives the product in lower yields, and the obtained polymer shows low trans-cis selectivity. Co complex with the ligand having 2,6-diisopropylphenyl groups at the coordinating nitrogen also promotes the cyclopolymerization to afford the polymer with cis-five-membered rings selectively. The polymerization is slower than the Fe-complex-catalyzed reaction, and the rate appears to be independent from the monomer concentration. Cyclopolymerization of the 1,6-heptadienes with phenyl or siloxy substituent at the 4-position is also catalyzed by the Fe and Co complexes in the presence of MMAO. The cyclization during the polymer growth occurs in similar trans-cis selectivity to that of unsubstituted 1,6-heptadiene. The Co complex, with addition of MMAO, catalyzes copolymerization of 1,6-heptadiene and ethylene to yield the copolymer having the trans-five-membered rings in the polyethylene chain, whereas the attempted copolymerization using the Fe catalyst gives a mixture of the homopolymers of the two monomers. The copolymerization by the Co catalyst involves chain transfer via beta-hydrogen elimination of the polymer after insertion of ethylene.

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“…Donohoe has disclosed details of the dihydroxylation of cyclic homoallylic alcohols directed by alcohol and trihaloacetamide groups. 41 The Sharpless asymmetric dihydroxylation (AD), using cinchona alkaloid-based ligands along with an osmium source and a stoichiometric co-oxidant, is one of the most reliable methods available for asymmetric synthesis. 42 One useful feature is the ease of prediction of enantiofacial selectivity using a mnemonic device.…”

Section: Alkene Dihydroxylationmentioning

confidence: 99%

3 Synthetic methods : Part (ii) Oxidation and reduction methods

Armstrong

Knight

2004

Annu. Rep. Prog. Chem., Sect. B

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As in last year's account, this Report will highlight work on some of the most commonly used oxidation and reduction reactions, particularly those allowing control of regio-and stereochemistry. The 2003 literature provides the vast majority of the content, with selected earlier references where needed to put the more recent work into context. The drive towards cleaner, cheaper, and more environmentally friendly reaction processes, as well as improved control over chemo-, regio-and stereoselectivity, particularly enantioselectivity, are continuing themes. Particular highlights include major developments in catalytic asymmetric conjugate reduction of enones, 1 particularly when incorporated into tandem conjugate reduction/aldol processes. 2 1 Oxidation reactions Alkene epoxidationThe development of more efficient catalytic methods for alkene epoxidation continues to receive intense interest. 3,4 For example, Stack has reported two new catalysts employing commercially available peracetic acid as co-oxidant.[Mn II (mcp)(CF 3 SO 3 ) 2 ]-catalyzed epoxidation proceeds via an electrophilic species, allowing regioselective epoxidation of carvone (Scheme 1), albeit with low diastereoselectivity. 5 This system does not display the selectivity for cis-alkenes over transalkenes that is typical for Mn(salen) epoxidations. In a second contribution, the same workers have developed a simple iron catalyst, [((phen) 2 (H 2 O)Fe III ) 2 (m-O)](ClO 4 ) 4 (phen ~phenanthroline) which will epoxidize a range of alkenes, including terminal ones (Scheme 2). 6 With allylic alcohol substrates, alcohol oxidation competes, while allyl acetate and cyclohexenone do not react. Styrenes can give product mixtures.Use of cleaner co-oxidants is an important focus. Epoxidations employing hydrogen peroxide for this purpose are attractive since the by-product is water, and progress in this area has been reviewed. 7,8 A highly efficient and recyclable

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Scope of the directed dihydroxylation: application to cyclic homoallylic alcohols and trihaloacetamides

Cited by 36 publications

References 25 publications

Synthesis of Cyclic and Macrocyclic Ethers Using Metathesis Reactions of Alkenes and Alkynes

Synthesis of Cyclic and Macrocyclic Ethers Using Metathesis Reactions of Alkenes and Alkynes

Selective cyclopolymerization of α,ω-dienes and copolymerization with ethylene catalyzed by Fe and Co complexes

3 Synthetic methods : Part (ii) Oxidation and reduction methods

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