Addition of Fluoroacetylenes to Group v Hydrides

Cullen, William R.; Dawson, David S.; Styan, G.E.

doi:10.1139/v65-471

Cited by 37 publications

(8 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The n.m.r. spectrum of the deutero adduct shows that the peak due to the (CH,),As group is split into a quartet as has been observed previously for compounds with this type of structure (7,12).…”

Section: Discussionsupporting

confidence: 75%

“…The and can be used as an aid to establish a mechanhydrogen-deuterium exchange reaction of reac-ism for the reaction. Table V shows some of the tion [7] when studied with neat liquids takes mechanistic possibilities for the trans addition. about 15 min for 50% equilibration at 35", and A similar table can be drawn up for the cis in dilute solution is so slow compared with the adducts.…”

Section: Reaction Mechanismmentioning

confidence: 99%

See 1 more Smart Citation

Kinetics and mechanism of the addition of dimethylarsine to hexafluorobutyne-2

Cullen¹,

Leeder²

1969

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

The addition of dimethylarsine to hexafluorobutyne-2 follows second order kinetics with activation energy, 6.09 k 0.20 kcallmole, and activation entropy, -48 k 1 e.u. The product distribution of the competitive reaction of din~ethylarsenic deuteride and diethylarsine with the acetylene shows that the addition mainly involves an intermolecular proton transfer. The mechanism of the addition is discussed.Canadian Journal of Chemistry, 47, 2137 (1969) Many investigations have been made of nucleophilic additions to acetylenes and a general rule of "trans addition" was postulated by Truce and Simms (1) and independently by Miller (2). This rule of stereospecific trans addition was based on product configuration. However, recently cis addition products have also been isolated (3, and references therein), mainly from reactions of primary and secondary amines, and with this 1 discovery, the question of the mechanism of . This reaction is clearly related to the amine additions and the present investigation was undertaken to establish if the mechanism of the arsine reaction involved a nucleophilic addition to form both products. It was also important to establish whether the hydrogen atom is transferred inter-or intra-molecularly. Experimental magnetic resonance (n.n~.r.) spectra were run on Varian A-60 and HA-100 instruments and are reported in p.p.m. downfield from external TMS. Ultraviolet (u.v.) spectra were recorded using a Cary Model 14 spectrophotometer; this was also used for the kinetic studies. Infrared (i.r.) spectra were run on a Perkin-Elmer Model 457 instrument. Prepamtion of Di~netl~ylarsit~eThe method used is a modification of that of Dehn and Wilcox (8). A 1-liter 3-necked flask was fitted with a dropping funnel, water-cooled condenser, stirrer, nitrogen purge, and cold traps (-196') to condense any volatile productscoming through the condenser. Mercuric chloride (30 g) and zinc dust (290 g) were placed in the flask and stirred vigorously with 100 ml of water. A solution of dimethylarsinic acid (50 g) in water (100 ml) was purged with nitrogen, transferred to the dropping funnel using a syringe, and combined with the slurry in the reaction flask. In a similar way 12 N hydrochloric acid (250 ml) was slowly added to the vigorously stirred flask. After 6 h, the contents of the traps were taken into the vacuum system and dried over PZO,. The yield of dimethylarsine was 34.1 g (89%). It had a very strong As-H stretching frequency at 2085 cm-' and the n.ni.r. spectrum showed a doublet at 0.82 p.p.m. (6H) and a septet a t 2.82 p.p.m. (IH) ( J C H~H = 7.0 HZ). Prepnrrrtiotz of Dimetl~ylnrse~~ic DeuterideDimethylarsine (10.8 g) was shaken with D 2 0 (30 g) and a trace of HCI (to speed exchange) for one week in a sealed tube. The arsine was separated and re-equilibrated with fresh D 2 0 . This yielded a product which is -100% (CH3),AsD as detected by n.ni.r.; (1 :1:1 triplet a t 0.82 p.p.m. ( J C H 3~ = 1 HZ)). The i.r. spectrum showed a strong As-D stretching band at 1502 cm-'.Volatile reagents and products wer...

show abstract

Section: Discussionsupporting

confidence: 75%

Section: Reaction Mechanismmentioning

confidence: 99%

Kinetics and mechanism of the addition of dimethylarsine to hexafluorobutyne-2

Cullen¹,

Leeder²

1969

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…but it is known that the alkynes with more electronwithdrawing substituents MeO 2 CC᎐ ᎐ ᎐ CCO 2 Me and F 3 CC᎐ ᎐ ᎐ CCF 3 can undergo double addition reactions of this sort, probably under radical conditions, to give diphosphines in each case. [13][14][15][16] The behaviour found here is summarised in Scheme 3 in which X is assumed to be bulkier than Y. Initial nucleophilic Michaellike attack by Ph 2 P Ϫ is on the ethynic carbon atom which carries the least bulky substituent as in (i) (syn) or (iii) (anti).…”

Section: (Ii) Addition Reactions With Ph 2 Phmentioning

confidence: 99%

Stereoselective addition of diphenylphosphine to substituted diphenylethynes: synthetic, NMR and X-ray crystallographic studies

Bookham¹,

Smithies²,

Wright³

et al. 1998

J. Chem. Soc., Dalton Trans.

View full text Add to dashboard Cite

The base-catalysed addition of diphenylphosphine to the substituted diphenylethynes RC᎐ ᎐ ᎐ CRЈ (R = Ph, RЈ = Ph, o-tolyl, m-tolyl or 2-biphenyl; R = m-tolyl, RЈ = o-tolyl or m-tolyl) yielded Ph 2 PC(R)᎐ ᎐ CHRЈ and/or Ph 2 PCH(R)CH(RЈ)PPh 2 . Proton, 13 C, 13 P and two-dimensional rotating frame Overhauser enhancement 1 H NMR spectra have been used to determine the stereochemical pathways of the reactions and the stereochemistry of the products. In general the more hindered alkynes undergo monoaddition ultimately to yield phosphinoalkenes with the Ph 2 P attached to the carbon bearing the least bulky substituent and cis to the olefinic proton, while for the less hindered alkynes the trans isomer is formed initially and this then reacts further to give meso/erythro-diphosphinoalkanes. Bis(o-tolyl)ethyne does not react with Ph 2 PH under the same conditions. Crystal structures were determined for E-and Z-Ph 2 P(Ph)C᎐ ᎐ CHPh and show distortions of interbond angles consistent with the pattern of strain implied by the foregoing reactions. The sulfides of the phosphinoalkenes and the Mo(CO) 4 complexes of the diphosphinoalkanes were also prepared and their 1 H, 13 C and 31 P NMR spectra recorded. In several cases the pattern of 13 CO NMR signals for the complexes was used unambiguously to determine the stereochemistry of the parent diphosphines.

show abstract

“…spectrum due to overlapping peaks in the 'H spectrum. Because the H-H couplings could not be established, the assignments are based on the finding that JF-H(,n,) in the cis isomer > JF-H(g,l,) in the trans isomer (13); this is also seen in 4 and 5. This assignment gives consistent values for the other couplings, especially the JH-H(t,alls~ of 15 c.p.s.…”

Section: Addition Of Difluorocarbene To the Olefizs Arzd Acetylenesmentioning

confidence: 99%

Stereochemistry of some olefins R_fCH=CHI and the preparation of some new cyclopropenes

Cullen¹,

Waldman²

1969

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

The light induced additions of CF3I and C2F5I to acetylene yield the trans 1:1 adducts predominantly [CF3CH=CHI (trans:cis = 6.7:1) and C2F5CH=CHI (trans:cis = 9:1)]. The addition of i-C3F7I to acetylene gives a 1:1 adduct consisting of a higher proportion of the cis isomer (trans:cis = 1.78:1). The i-C3F7I-acetylene adduct can be dehydrohalogenated to produce i-C3F7C≡CH. Difluorocarbene (from (CH3)3SnCF3) does not add to the olefinic 1:1 adducts but does add to the polyfluoroalkyl acetylenes RfC≡CH to produce the cyclopropenes [Formula: see text]

show abstract

Addition of Fluoroacetylenes to Group v Hydrides

Cited by 37 publications

References 7 publications

Kinetics and mechanism of the addition of dimethylarsine to hexafluorobutyne-2

Kinetics and mechanism of the addition of dimethylarsine to hexafluorobutyne-2

Stereoselective addition of diphenylphosphine to substituted diphenylethynes: synthetic, NMR and X-ray crystallographic studies

Stereochemistry of some olefins R_fCH=CHI and the preparation of some new cyclopropenes

Contact Info

Product

Resources

About

Addition of Fluoroacetylenes to Group v Hydrides

Cited by 37 publications

References 7 publications

Kinetics and mechanism of the addition of dimethylarsine to hexafluorobutyne-2

Kinetics and mechanism of the addition of dimethylarsine to hexafluorobutyne-2

Stereoselective addition of diphenylphosphine to substituted diphenylethynes: synthetic, NMR and X-ray crystallographic studies

Stereochemistry of some olefins RfCH=CHI and the preparation of some new cyclopropenes

Contact Info

Product

Resources

About

Stereochemistry of some olefins R_fCH=CHI and the preparation of some new cyclopropenes