Propargylation of Alkyl Halides: (
            <i>E</i>
            )‐6,10‐dimethyl‐5,9‐undecadien‐1‐yne and (
            <i>E</i>
            )‐7,11‐dimethyl‐6,10‐dodecadien‐2‐yn‐1‐ol

Hooz, John; Cabezas, Jorge A.; Musmanni, Sergio; Calzada, José G.

doi:10.1002/0471264180.os069.15

Cited by 6 publications

(17 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10 An indirect procedure employing 3-lithio-1-trimethylsilylpropyne initially produces the trimethylsilylprotected acetylene, from which the required homologated alkyne is liberated by reaction with ethanolic silver nitrate followed by sodium cyanide. 11 We previously reported 12 the preparation of the operational equivalent of the propargyl dianion (5) from treatment of allene (6) with 2 equiv of n-BuLi (Scheme 2). This dianion (5) regiospecifically reacted with aromatic aldehydes and ketones to produce homopropargyl alcohols (3) in very good yields (Scheme 2, method A).…”

Section: ■ Introductionmentioning

confidence: 99%

“…13 An additional advantage of this methodology is that the initially formed lithium acetylide intermediate (7) may be further transformed, in situ, into other derivatives (8) by adding electrophiles such as paraformaldehyde, iodomethane, trimethylsilyl chloride, and ethyl chloroformate. 12,14 When this methodology was used with aliphatic aldehydes or ketones, mixtures of allenic and acetylenic isomers, favoring the latter (2:8), were obtained. Fortunately, we found that these mixtures of allenyl and homopropargyl alcohols can be quantitatively converted to the corresponding homopropargyl alcohols by a zipper reaction.…”

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Palladium-Catalyzed One-Pot Conversion of Aldehydes and Ketones into 4-Substituted Homopropargyl Alcohols and 5-En-3-yn-1-ols

Umaña

Cabezas

2017

J. Org. Chem.

View full text Add to dashboard Cite

Sequential treatment of 2,3-dichloropropene with magnesium and n-BuLi generated the equivalent of 1,3-dilithiopropyne, which adds regiospecifically to aldehydes and ketones to produce homopropargyl alcohols. The lithium acetylide intermediate formed in this protocol can be further reacted with aromatic and vinyl halides, under palladium catalysis, to produce 4-substituted homopropargyl alcohols and 5-en-3-yn-1-ols, respectively, in one-pot with good overall yields.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Palladium-Catalyzed One-Pot Conversion of Aldehydes and Ketones into 4-Substituted Homopropargyl Alcohols and 5-En-3-yn-1-ols

Umaña

Cabezas

2017

J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…The reaction was warmed to room temperature and stirred for 5 h. Sat. 37 (2E)-3-Bromo-7-methylocta-2,6-dien-1-ol (4a). NaCl (50 ml) was added and the solution was extracted with petroleum ether (3 × 50 ml).…”

Section: Modelling Studiesmentioning

confidence: 99%

“…R f 0.40 (1 : l hexanesether); data: (lit. 37 ) 1 H NMR (400 MHz, CDCl 3 ) δ: 5.16 (m, 1H), 5.09 (m, 1H), 4.25 (d, 2H, J = 10.8), 2.22 (narrow m, 4H), 2.07 (m, 2H), 1.99 (m, 2H), 1.68 (s, 3H), 1.61 (s, 3H), 1.60 (s, 3H), 1.50 (t, 1H, J = 10.8), 13 C NMR (400 MHz, CDCl 3 ) δ: 133. (2E)-3-Bromo-7-methylocta-2,6-dien-1-ol (4a).…”

Section: Modelling Studiesmentioning

confidence: 99%

Inhibition of a multiproduct terpene synthase from Medicago truncatula by 3-bromoprenyl diphosphates

et al. 2015

View full text Add to dashboard Cite

The multiproduct sesquiterpene synthase MtTPS5 from Medicago truncatula catalyzes the conversion of farnesyl diphosphate (FDP) into a complex mixture of 27 terpenoids. 3-Bromo substrate analogues of geranyl diphosphate (3-BrGDP) and farnesyl diphosphate (3-BrFDP) were evaluated as substrates of MTPS5 enzyme. Kinetic studies demonstrated that these compounds were highly potent competitive inhibitors of the MtTPS5 enzyme with fast binding and slow reversibility. Since there is a lack of knowledge about the crystal structure of multiproduct terpene synthases, these molecules might be ideal candidates for obtaining a co-crystal structure with multiproduct terpene synthases. Due to the structural and mechanistic similarity between various terpene synthases we expect these 3-bromo isoprenoids to be ideal probes for crystal structure studies.

show abstract

“…Further useful dianions can be generated from ketones (C=C(OM)CM or C=C(OM)CCM) [138][139][140][141][142], carboxylic acids (C=C(OM) 2 ) [143][144][145], succinic acid derivatives ((C=C(OM)OR) 2 ) [146], alkynes (MC"CCM, MC"CC-OM) [147][148][149][150][151][152][153][154][155], imidazoles [156], thiophenes [157,158], b-alanine derivatives (MN-CC=C(OM)X) [159], 3-nitropropanoates [160,161], 3-hydroxypropanoates [162,163], 2-hydroxyethylsulfones [164,165], arenes [166][167][168], allenes [169], thioamides [170], and sulfonamides (MC-SO 2 NM [171]; R 2 NSO 2 -CM 2 [172]). If the nucleophilic sites in the polyanion have different chemical hardness, regioselective alkylation can be achieved by selecting a soft or a hard electrophile (second reaction, Scheme 5.13).…”

Section: 36mentioning

confidence: 99%

The Alkylation of Carbanions

Dörwald

2004

Side Reactions in Organic Synthesis

View full text Add to dashboard Cite

The deprotonation of organic compounds by strong, non-nucleophilic bases followed by C-alkylation with a suitable electrophile has become one of the most predictable and straightforward methods for formation of C-C bonds. The popularity of this chemistry is also a consequence of the often-seen close resemblance of feasible structural modifications by a deprotonation/alkylation strategy to an unsophisticated retrosynthetic analysis of a given target compound. Other reactions, which involve, for instance, substantial rearrangement of the carbon framework (e.g. Cope rearrangement, fragmentations, ring contractions or enlargements) are usually more difficult to take into account during retrosynthetic analysis.LDA and related, sterically hindered, lithium dialkylamides, first investigated by Levine [1], have completely replaced the more nucleophilic sodium amide, which had been the base of choice for many years [2]. Because the reactivity of an organometallic compound depends to a large extent on its state of aggregation (i.e. on the solvent and on additives) and on the metal, transmetalation of the lithiated intermediates and the choice of different solvents and additives emerged as powerful strategies for fine-tuning the reactivity of these valuable nucleophiles.In this chapter the alkylation of carbanions with simple carbon electrophiles will be discussed, with special emphasis on the structure-reactivity relationship of the carbanion and on side reactions. In this context the term "carbanion" refers to an intermediate prepared by in-situ deprotonation of an organic compound, followed by optional cation exchange (transmetalation), which tends to be alkylated at carbon by soft electrophiles such as MeI or PhCHO. This type of reactivity is characteristic of enolates with an ionic M-O bond or for organometallic compounds with a strongly polarized or ionic M-C bond, M typically being an alkali metal, Mg, Cu, or Zn. Carbanions can, alternatively, also be prepared by halogen-metal exchange [3-8], sulfoxide-or sulfone-metal exchange [9-13], or by transmetalation of stannanes. The most suitable reagents for performing such metalating exchange reactions are organometallic compounds with a metal-bound secondary or tertiary alkyl group, such as tBuLi, sBuLi, iPr 2 Zn [14, 15], or iPrMgHal [6]. These reagents are thermodynamically less stable than organometallic compounds with primary alkyl 5 146 Scheme 5.1. Approximate relative rates of proton transfer in water at thermoneutrality (DpK a = 0) [35, 39, 51]. 147 Scheme 5.2. The effect of fluorine on the acidity of organic compounds [24, 62-65]. 148 Scheme 5.3. Dependence of the reactivity of carbanions on their basicity [68, 72-74]. Regioselectivity of Deprotonations and AlkylationsThe organic chemist is occasionally confronted with the problem that a compound has several differrent X-H groups of similar pK a . If only one of these is to be alkylated, one option would be to perform a regioselective deprotonation. This can sometimes be achieved by exploiting small differences be...

show abstract

Propargylation of Alkyl Halides: ( E )‐6,10‐dimethyl‐5,9‐undecadien‐1‐yne and ( E )‐7,11‐dimethyl‐6,10‐dodecadien‐2‐yn‐1‐ol

Cited by 6 publications

References 16 publications

Palladium-Catalyzed One-Pot Conversion of Aldehydes and Ketones into 4-Substituted Homopropargyl Alcohols and 5-En-3-yn-1-ols

Palladium-Catalyzed One-Pot Conversion of Aldehydes and Ketones into 4-Substituted Homopropargyl Alcohols and 5-En-3-yn-1-ols

Inhibition of a multiproduct terpene synthase from Medicago truncatula by 3-bromoprenyl diphosphates

The Alkylation of Carbanions

Contact Info

Product

Resources

About