Stereochemistry of the electrophilic ring opening of cyclopropanes. 2. Reaction of cis- and trans-1,2,3-trimethylcyclopropane with deuterium(1+) ion

DePuy, Charles H.; Fuenfschilling, Peter C.; Andrist, A. Harry; Olson, J. M.

doi:10.1021/ja00461a019

Cited by 16 publications

(4 citation statements)

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“…Cyclopropane, 6a ,33a and methyl-, 6b ;33a 1,1-dimethyl-, 6c ;33a cis-1,2-dimethyl, 6d ;33a trans-1,2-dimethyl-, 6e ;33a 1,1,2-trimethyl-, 6f ;33a cis-1,2,3-trimethyl-, 6g ;33b and trans-1,2,3-trimethylcyclopropane, 6h 33b (Figure ) serve as simple model compounds to aid assignment of the 13 C NMR spectra of poly-3a . The γ-syn effect of a CH 3 group imposed on another CH 3 substituent leads to an upfield shift of Δδ = −6.0 to −6.8 ppm and is approximately additive for a third methyl substituent (compare 6b with 6d and 6g , and compare 6c with 6f ).…”

Section: Resultsmentioning

confidence: 99%

Palladium(II)-Catalyzed Olefin Addition Polymerizations of 3,3-Dialkyl-Substituted Cyclopropenes

1997

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Ionic (η3-allyl)palladium complexes containing bidentate 2,2‘-bipyridyl, sparteine and C2-symmetric bisoxazoline ligands and weakly coordinating anions catalyze the addition polymerization of 3,3-dialkylcyclopropenes. Poly(3,3-dimethylcyclopropene), poly(3-ethyl-3-methylcyclopropene) and poly(3-n-pentyl-3-methylcyclopropene) with molecular weights M n(GPC) above 10 000 are formed which are nearly exclusively composed of triangular repeating units. In contrast, partial ring-opening occurs during polymerizations with ionic palladium tetrakis(nitrile) complexes [Pd(RCN)4][BF4]2 which contain relatively labile nitrile ligands. The latter reactions lead to polymers which contain approximately 50% ring-opened unsaturated repeating units. The polymerizations carried out in the presence of the C2-symmetric phenyl-substituted bisoxazoline ligand and with the (−)-sparteine-based catalyst lead to partially stereoregular polymers which contain a slight excess of meso units. Assignment of 13C NMR spectra was aided with a quatercyclopropyl model compound composed of exclusively racemic units. The polycyclopropenes are partially crystalline and show a relatively good short term thermal stability with TGA investigations indicating onset of thermally induced weight loss above 280 °C.

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Section: Resultsmentioning

confidence: 99%

Palladium(II)-Catalyzed Olefin Addition Polymerizations of 3,3-Dialkyl-Substituted Cyclopropenes

1997

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“…6) [74] is replaced by two hydroxy groups, (2R,3S)-butanediol is obtained. In cistrimethyl-cyclopropane and trans-trimethyl-cyclopropane [75], the apex intersected by the mirror plane of symmetry cannot be replaced by two methyl groups since the chirality of the other two cyclopropane groups is anihilated. Consequently, that apex would be replaced by two imaginary R residues.…”

Section: Fig 1 a Comparison Of Planes Of Symmetry Of Some Disubstitut...mentioning

confidence: 99%

Meso Compounds Systematization ‒ A Chemical Paradox among Inositols and a Group of Super-symmetric Combinations

Iga

2024

AJRB

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Meso Compounds have been defined by themselves, as well as by their relationship with another group of diastereomeric combinations, C2 symmetrical ones, isomer to meso. Every meso compound should present a homodimer equivalent able to display at least one C2 symmetrical isomer. Cahn-Ingold-Prelog test, however limited, is also valuable. A systematization of meso combinations includes the following types: (A) meso Homodimers possessing one super-symmetric isomer or two real or envisaged C2 symmetrical enantiomers; (B) meso Heterodimers with a binding support having geometric or optical symmetry (e.g. >CR2, etc.). (C) meso Heterodimers with a binding support devoid of symmetry (of the form >CRR’, etc.), seeable as meso, and provable in this way not by themselves but by their equivalent meso homodimers. A paradoxical behavior has been shown at one of inositol isomers, in comparison with the others. Moreover, a new group of compounds has been disclosed, which are concomitantly meso and C2 symmetrical, and of this reason they have been called super- symmetrical.

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“…corner protonated cyclopropane which is formed by a proton-slide (9) to the corner after initial edgeapproach.…”

Section: ' W H I L E R E T E N T I O N O F C O N F I G U R a T I O N mentioning

confidence: 99%

Stereochemistry of acid-catalyzed cleavage of 3-chloro- and 3-bromonortricyclene in deuterated medium. Evidence for edge protonation of nortricyclenes

Timmins¹,

Cappelli²

1980

Can. J. Chem.

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M c M a s t e r Utli~:rrsity, Hnmiltorl, Otlr., C a n a d r i L8S 4 M I R e c e i v e d D e c e m b e r 5. 1979 N I C K H E N R Y W E R S~I U K , GEORGE TIMMINS, a n d FRANK PETER CAPPELLI. C a n . J. C h e m . 58, 1709 (1980). C l e a v a g e o f 3-chloronortricyclene (4c) a n d 3 -b r o m o n o r t r i c y c l e n e (4d) o c c u r s f a s t e r t h a n solvolysis in D , S 0 4 -D O A c a t 70-75°C a n d yields sytl-7-, a t~t i -7 -, exo-5-, a n d erl(1o-5-halo-e.ro-2-norbornyl a c e t a t e s a s p r o d u c t s . T h a t t h e 7 -c h l o r o a c e t a t e s c o m p r i s e 70% o f t h e r e a c t i o n m i x t u r e , t h a t 30%of t h e 5-chloro-eso-2-norbornyl a c e t a t e s w h i c h c o m p r i s e d 28%of t h e r e a c t i o n m i x t u r e a r e d e r i v e d v i a r e a r r a n g e m e n t o f t h e sytl-7-a n d a n t i -7 -c h l o r o n o r b o r n y l c a t i o n s , a n d t h a t t h e d e u t e r i u m a t C -6 i s a t l e a s t 90% s t e r e o c h e m i c a l l y p u r e ~n d o is e v i d e n c e t h a t c l e a v a g e o f t h e b o n d f a r t h e s t r e m o v e d f r o m t h e e l e c t r o n w i t h d r a w i n g h a l o g e n i s p r e f e r r e d 5: 1 o v e r t h e o t h e r b o n d s o f t h e t h r e e -m e m b e r e d ring. T h e s t e r e o c h e m i s t r y o f t h e ring-opening i s r a t i o n a l i z e d o n t h e basis o f c l e a v a g e v i a e d g ed e u t e r o n a t i o n w i t h f o r m a t i o n o f classical h a l o c a t i o n s a s i n t e r m e d i a t e s . T h e l o c a t i o n o f d e u t e r i u m in t h e 5-halo-elo-norbornyl a c e t a t e s is u s e d t o define t h e p a t h w a y s w h e r e b y t h e5 -h a l o a c e t a t e s a r e f o r m e d . T h i s s t u d y a l s o e s t a b l i s h e s t h a t C -6 e t l d o d e u t e r a t e d 7-chloro-a n d 7-bromo-exo-2-norbornyl b r o s y l a t e s c a n b e s y n t h e s i z e d f r o m t h e c o r r e s p o n d i n g 3-halonortricyclenes. N I C K H E N R Y WERSTIUK, G~O R G ETIMMINS e t FRANK PETER CAPPELLI. C a n . J. C h e m . 5 8 , 1 7 0 9 (1980). L e clivage d e s c h l o r o -3 e t b r o m o -3 n o r t r~c y c l e n e s ( 4 c ) e t ( 4 4 s e p r o d u i t p l u s r a p i d e m e n t q u e l a s o l v o l y s e d a n s l e m e l a n g e D , S 0 4 -D O A c B 70-75°C e t c o n d u i t a u x a c e t a t e s d e s halogeno-7-syrl, 7-clrlt1, 5 -e s o e t 5-erldo n o r b o r n y l e s -2 -e s o . L e fait q u e ( ( 1 ) l e s a c e t a t e s d e s c h l o r o -7 n o r b o r n y l e s c o n s t i t u e n t 70% d u m e l a n g e r e a c t i o n n e l , (b) 30% d e s a c e t a t e s d e s c h l o r o -5 norbornyles-2-eso, q u i c o n s t i t u e n t 28% d u m e l a n g e r e a c t i o n n e l , p r o v l e n n e n t d e l a t r a n s p o s i t i o n d e s c a t i o n s c h l o r o -7 sytl e t 7-(inti n o r b o r n y l e s e t ( c ) l e d e u t e r i u m e n C -6 e s t a u m o i n s a 90% e n d o m o n t r e q u e l e clivage d e l a liaison l a p l u s eloignke d e I'halogene Clectro-attracteur se fait preferentiellement ...

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Stereochemistry of the electrophilic ring opening of cyclopropanes. 2. Reaction of cis- and trans-1,2,3-trimethylcyclopropane with deuterium(1+) ion

Cited by 16 publications

References 5 publications

Palladium(II)-Catalyzed Olefin Addition Polymerizations of 3,3-Dialkyl-Substituted Cyclopropenes

Palladium(II)-Catalyzed Olefin Addition Polymerizations of 3,3-Dialkyl-Substituted Cyclopropenes

Meso Compounds Systematization ‒ A Chemical Paradox among Inositols and a Group of Super-symmetric Combinations

Stereochemistry of acid-catalyzed cleavage of 3-chloro- and 3-bromonortricyclene in deuterated medium. Evidence for edge protonation of nortricyclenes

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