Deoxygenation of alcohols by the reactions of their xanthate esters with triethylsilane: An alternative to tributyltin hydride in the Barton-McCombie reaction

Kirwan, J. Nicholas; Roberts, Brian P.; Willis, Caroline

doi:10.1016/s0040-4039(00)97814-6

Cited by 56 publications

(6 citation statements)

References 20 publications

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“…Finally, there have been no studies on whether the phosphane-ene reaction can be performed in conjunction with the thiol-ene process despite their similar mechanisms. There is evidence that thiols behave catalytically and improve radical additions of other elements to double bonds, 24,25 but this has not been an examined for primary phosphines. Such an approach would allow for the fabrication of phosphorussulfur hybrid materials possessing characteristics of both systems, further developing the toolbox for inorganic-element containing polymers.…”

Section: Introductionmentioning

confidence: 99%

Phosphane–ene chemistry: the reactivity of air-stable primary phosphines and their compatibility with the thiol–ene reaction

2015

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Air-sensitive and air-stable primary phosphines (RPH2) were compared for their ability to undergo photoinitiated phosphane-ene chemistry with 1-hexene. Despite their increased air-stability, the primary phosphines displayed equal to or greater reactivity when compared to air-sensitive alkyl or aryl analogues. The phosphane-ene reaction was also performed in the presence of 1-octanethiol to determine whether thiol-ene and phosphane-ene chemistries could proceed simultaneously. It was determined that the phosphane-ene process takes precedence over thiol-ene as P-H bond conversion was independent of thiol concentration. Tertiary phosphine (R3P) and some secondary phosphine (R2PH) products were found to react with thiols under experimental conditions to create phosphine-sulfides (P-S), but this chemistry only proceeded at low P-H bond concentrations. These results suggests that hydrogen transfer reactions take precedence over P-S formation and demonstrate the unique relationship between phosphane-ene and thiol-ene chemistry.

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Section: Introductionmentioning

confidence: 99%

Phosphane–ene chemistry: the reactivity of air-stable primary phosphines and their compatibility with the thiol–ene reaction

2015

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“…[21] It takes advantage of the radicophilic nature of the thiocarbonyl group, especially in O-phenoxythiocarbonyl derivatives of alcohols as introduced by Robins et al, [22] but suffers the drawback of relying on tributylstannane as reducing agent, which leads to the formation of toxic and smelly tin-containing byproducts. Roberts et al, [23] and Schummer and Höfle, [24] however, demonstrated that this disadvantage can be avoided by employing organosilanes as radical-based reducing agents [25] in the Barton-McCombie reaction. For the deoxygenation of compound 13, the procedure of Schummer and Höfle [24] was followed, which uses tris(trimethylsilyl)-silane (TTMSS) as reagent.…”

Section: Resultsmentioning

confidence: 99%

Total Synthesis and Olfactory Evaluation of (1R,3S,6S,7S,8S*)‐ 3‐Hydroxy‐6,8‐dimethyltricyclo[5.3.1.0^3,8]undecan‐2‐one: A New Synthetic Route to the Patchoulol Skeleton

Kraft¹,

Weymuth²,

Nussbaumer³

2006

Eur J Org Chem

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The superposition analysis of (–)‐patchoulol (1), the odorous principle of patchouli oil, with the recently discoveredhigh‐impact spirocyclic patchouli odorant (+)‐(1S,4R,5R,9S)‐1‐hydroxy‐1,4,7,7,9‐pentamethylspiro[4.5]decan‐2‐one (2) resulted in the question as to whether a patchoulolderivative in which the gem‐dimethyl group is replacedby a carbonyl function would be a powerful patchouliodorant. The total synthesis of the racemic superstructure (1R*,3S*,6S*,7S*,8S*)‐3‐hydroxy‐6,8‐dimethyltricyclo[5.3.1.03,8]undecan‐2‐one (3) was accomplished in 13 steps from the inexpensive commercial odorant Cyclal C (7) with a total yield of 7 %. Conversion of 7 to the corresponding enamine 8 and subsequent copper‐catalyzed oxidative degradation afforded 2,4‐dimethylcyclohex‐3‐enone (6), which was subjected to a Robinson annulation with 1,4‐dimethoxybutan‐2‐one (9). The carbonyl function of the resulting annulation product 10 was removed by LAH reduction, acylation with Ac2O, and dissolving metal reduction. The deoxygenated methyl enol ether 12 thus obtained was then cleaved by mild hydrolysis with oxalic acid, and the resulting 2,9‐dimethyl‐Δ1‐octalin‐5‐one (5) was hydroxymethylenated by Claisen ester condensation with ethyl formate to provide thecis‐configured (2Z)‐2,3,4,4a,8,8a‐hexahydro‐2‐(hydroxymethylene)‐4a,6‐dimethylnaphthalen‐1(7H)‐one (4). In a novel intramolecular Prins reaction with an equimolar amount of p‐toluenesulfonic acid monohydrate, the ideally preformed precursor 4 cyclized to (1R*,2R*,3S*,7R*,8S*)‐2‐hydroxy‐4,8‐dimethyltricyclo[5.3.1.03,8]undec‐4‐en‐11‐one (13), comprising the complete carbon framework of the target compound 3. A Barton–McCombie deoxygenation of the corresponding O‐phenoxythiocarbonyl derivative, followed by oxidation of the lithium enolate of the resulting ketone 14 with the molybdenum peroxide reagent MoO5–pyridine–DMPU, and the face‐selective hydrogenation of the obtained(1R*,3S*,7S*,8S*)‐3‐hydroxy‐6,8‐dimethyltricyclo[5.3.1.03,8]undec‐5‐en‐2‐one (15) concluded the synthesis of the target molecule 3, which was accompanied by its odorless C‐6 epimer epi‐3 in the ratio 84:16. Both the target structure 3 and its unsaturated precursor 15 possessed pronounced patchouli odors, albeit slightly weaker in threshold than (–)‐patchoulol (1). This proved the superposition analysis of the templates 1 and 2 to be correct and provided novel insight into the structural requirements of patchouli odorants. As 3 was an intermediate in a total synthesis of rac‐1, the synthesis also constitutes a new formal total synthesis of racemic patchoulol (rac‐1). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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“…39,103,127,128 More economical alternatives were sought, such as arylsilanes 129–131 and trialkylsilanes. 132 In comparative studies of the hydrogen transfer capacity between various alkyl or arylsilanes and tributyltin, using d -Glc f derivative 56 as a substrate for the deoxygenation, the order of reactivity indicated in Scheme 23 was established. 130…”

Section: Deoxygenation Methodsmentioning

confidence: 99%

Deoxy sugars. General methods for carbohydrate deoxygenation and glycosidation

Marino

Bordoni

2022

Org. Biomol. Chem.

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Deoxygenation of alcohols by the reactions of their xanthate esters with triethylsilane: An alternative to tributyltin hydride in the Barton-McCombie reaction

Cited by 56 publications

References 20 publications

Phosphane–ene chemistry: the reactivity of air-stable primary phosphines and their compatibility with the thiol–ene reaction

Phosphane–ene chemistry: the reactivity of air-stable primary phosphines and their compatibility with the thiol–ene reaction

Total Synthesis and Olfactory Evaluation of (1R,3S,6S,7S,8S*)‐ 3‐Hydroxy‐6,8‐dimethyltricyclo[5.3.1.0^3,8]undecan‐2‐one: A New Synthetic Route to the Patchoulol Skeleton

Deoxy sugars. General methods for carbohydrate deoxygenation and glycosidation

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Deoxygenation of alcohols by the reactions of their xanthate esters with triethylsilane: An alternative to tributyltin hydride in the Barton-McCombie reaction

Cited by 56 publications

References 20 publications

Phosphane–ene chemistry: the reactivity of air-stable primary phosphines and their compatibility with the thiol–ene reaction

Phosphane–ene chemistry: the reactivity of air-stable primary phosphines and their compatibility with the thiol–ene reaction

Total Synthesis and Olfactory Evaluation of (1R*,3S*,6S*,7S*,8S*)‐ 3‐Hydroxy‐6,8‐dimethyltricyclo[5.3.1.03,8]undecan‐2‐one: A New Synthetic Route to the Patchoulol Skeleton

Deoxy sugars. General methods for carbohydrate deoxygenation and glycosidation

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Product

Resources

About

Total Synthesis and Olfactory Evaluation of (1R,3S,6S,7S,8S*)‐ 3‐Hydroxy‐6,8‐dimethyltricyclo[5.3.1.0^3,8]undecan‐2‐one: A New Synthetic Route to the Patchoulol Skeleton