Total syntheses of (R)-argentilactone and (R)-goniothalamin via catalytic enantioselective allylation of aldehydes

Fátima, Ângelo de; Pilli, Ronaldo A.

doi:10.1016/j.tetlet.2003.09.122

Cited by 49 publications

(13 citation statements)

References 24 publications

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“…When the metathesis was carried out at higher concentrations ( % 0.1 m), the yields did not exceed 20 %. These results are in agreement with previously reported results [17] and a recent study regarding Table 2. B97D/cc-pVTZ energetics [13] of the coupling between crotylaldehyde and allyltrichlorosilane.…”

supporting

confidence: 94%

Lewis Base Catalyzed Enantioselective Allylation of α,β‐Unsaturated Aldehydes

Kadlčíková

Valterová

Ducháčková

et al. 2010

Chemistry A European J

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The invention and development of highly enantioselective catalytic reactions with a low catalyst loading is one of the current challenges in organic chemistry. One such area is the activation of reactants by Lewis base/acid pairing.[1] Especially attractive in this regard is the enantioselective allylation of carbonyl compounds (Sakurai-Hosomi reaction) with allylmetals to give chiral homoallylic alcohols that can be used as building blocks in the synthesis of complex molecules. [2] In the last decade, considerable attention has been paid to a possible variant of this reaction based on the activation of allyltrichlorosilane or its derivatives by chiral Lewis bases, such as pyridine N-oxides. A variety of bi-or monodentate [2][3][4][5][6] catalysts have been synthesized and applied in the catalytic allylation of aromatic aldehydes, which is used as a benchmark reaction to assess the catalytic activity and the scope of asymmetric induction. Although in some cases high enantioselectivity was observed, this trend was not general and the asymmetric induction was often highly dependent on the presence of electron-accepting or -donating groups. Another problem is the synthesis of the catalyst being often complicated.We showed that the above-mentioned problems could be overcome by the use of unsymmetrical diastereoisomeric bis(tetrahydroisoquinoline) N,N'-dioxides 1 and appropriate choice of solvent.[7] Lewis bases 1 were prepared in three steps by a one-pot microwave-induced cross-cyclotrimerization [8] of hexadecatetrayne with benzonitrile and (R)-tetrahydrofurannitrile followed by oxidation with MCPBA.The presence of the additional center of chirality within the molecular framework allowed easy separation of both diastereoisomers by using simple column chromatography on silica gel. The correct configuration was unequivocally confirmed by a single-crystal X-ray analysis (Figure 1). Second, the allylation of various benzaldehydes catalyzed by 1 (1 mol %, À78 8C, 1 h) in THF proceeded with high enantioselectivity (up to 96 %) and high yields regardless of electronic properties of the substituents on the aromatic ring. [7a] Although the N-oxide-catalyzed allylation of benzaldehydes has been extensively studied, the reaction with a,bunsaturated aldehydes has been rather neglected. There have been reported allylations of three aldehydes: cinnamaldehyde, [3, 4b,c, 5b-d, 9-11] a-methylcinnamaldehyde, [5c, 9] and 2-decenal [3] with maximum enantioselectivities of 83, 76, and 81 % ee, respectively. The lack of data in this area provided the necessary impetus to study enantioselective allylation by using 1.Initially, the allylation of cinnamaldehyde 2 a with allyltrichlorosilane in the presence of (R,R)-1 (1 mol %, 1 h) was carried out in various solvents and gave 3 a with the following results: 92 % yield, 97 % ee in THF; 40 % yield, 88 % ee in dichloromethane; 43 % yield, 88 % ee in toluene; 84 % yield, 96 % ee in methoxycyclopentane; and 52 % yield, 96 % ee in 2-methylTHF [12] . Interestingly, the reaction in MeCN did n...

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confidence: 94%

Lewis Base Catalyzed Enantioselective Allylation of α,β‐Unsaturated Aldehydes

Kadlčíková

Valterová

Ducháčková

et al. 2010

Chemistry A European J

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“…The total mass recovery of materials is reported. The major components of each pyrolysate mixture were identified by characteristic 1 6.01 ppm (1H, ddd)] were used to estimate the relative quantities of each of these components of the pyrolysates. Unidentified degradation components which gave rise to broad resonances began to appear at 700 8C and were significant at 800 and 850 8C.…”

Section: Flash Vacuum Pyrolysis Of Argentilactonementioning

confidence: 99%

Flash vacuum pyrolysis of argentilactone

McNab

Priestap

Tyas

2007

Journal of Analytical and Applied Pyrolysis

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“…Because of the quantity of work in this area (more than 60 publications) it has proved impossible to include all contributions made over the last five years, and we apologize to those workers whose contributions to this area are not included. This strategy was first described by Ghosh in the synthesis of peptide isosteres, [30] and was then used in a number of total syntheses including those of argentilactone, [31,32] goniothalamin, [31,33,34] callystatin, [35] boronolide, [36] strictifolione, [37] hexadecanolide, [34] massoia lactone, [34] parasorbic acid, [34] passifloricin A, [38] spicigerolide, [39] anamarine, [40] and fostriecin [41] (Scheme 14). A RCM on an homoallylic alcohol protected as an allyl ether, followed by an oxidation, has also been described in the total synthesis of gonotriol.…”

Section: 1) Rcm CM and Tandem Rc/cm Strategies From Homoallylic Amentioning

confidence: 99%

Synthetic Approaches to α,β‐Unsaturated δ‐Lactones and Lactols

2006

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The synthesis of six‐membered unsaturated δ‐lactones has generated considerable interest, due to their occurrence in a large number of natural products possessing potent biological activities. This microreview attempts to illustrate the different strategies used to obtain such compounds, with a special emphasis on catalytic and asymmetric approaches. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

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Total syntheses of (R)-argentilactone and (R)-goniothalamin via catalytic enantioselective allylation of aldehydes

Cited by 49 publications

References 24 publications

Lewis Base Catalyzed Enantioselective Allylation of α,β‐Unsaturated Aldehydes

Lewis Base Catalyzed Enantioselective Allylation of α,β‐Unsaturated Aldehydes

Flash vacuum pyrolysis of argentilactone

Synthetic Approaches to α,β‐Unsaturated δ‐Lactones and Lactols

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