5889-54-3

Usage

InChI:InChI=1/C7H9Br/c8-7-4-5-1-2-6(7)3-5/h1-2,5-7H,3-4H2

Upstream product

• 121-46-0 bicyclo[2.2.1]hepta-2,5-diene 
• 71338-98-2 p-Toluolsulfonsaeure-<6endo-brom-2endo-norbornyl>ester 
• 71338-98-2 p-Toluolsulfonsaeure-<6-endo-brom-2exo-norbornyl>ester 
• 71338-98-2 p-Toluolsulfonsaeure-(6exo-brom-2exo-norbornyl)ester 
• 593-60-2 Vinyl bromide 
• 542-92-7 cyclopenta-1,3-diene 

Downstream Products

• 498-66-8 norborn-2-ene 
• 279-19-6 nortricyclane 
• 21942-28-9 3-nortricyclyltrimethyltin 
• 21957-51-7 endo-2-norbornene-5-yl-trimethyl tin 
• 2534-77-2 exo-2-bromonorbornane 

Relevant academic research and scientific papers

The Surface Nature of Grignard Reagent Formation

The reaction of exo-2-norbornyl bromide with Rieke magnesium in ether at -70 deg C in the presence of tert-butyl alcohol-O-d gave exclusively exo-2-deuterionorbornane whereas the epimer endo-2-norbornyl bromide yielded a 1:1 mixture of endo- and exo-2-deu

Synthese und Hydrolyse von 6endo-substituierten p-Toluolsulfonsaeure-estern.

The Synthesis and Hydrolysis of 6endo-Substituted 2endo-Norbornyl p-Toluenesulfonates; The hydrolysis products of the p-toluenesulfonates of several hitherto unknown 6endo-substituted 2endo-norbornanols have been determined.

Synthesis of some 1,2-Dihalogenonorbornanes

The synthesis of 1,2exo-dibromo-norbornane as well as the preparation of the configurational isomers of 2-bromo-1-iodo- and 2-chloro-1-iodo-norbornane are described.

Polar versus Steric Effects in the Solvolysis of 6endo-substituted 2endo-Norbornyl p-Toluenesulfonates

The solvolysis rates and products of the 6endo-R-substituted 2endo-norbornyl toluenesulfonates 6a-6i have been determined.The rates of 6a-6g correlate with the inductive constants ?qI of the 6endo-substituents and are not related to the size of the latter.It is therefore concluded that polar rather than steric effects control the exo/endo-rate ratios of norbornyl sulfonates.Products are derived mainly from rearranged 6exo-R-norbornyl cations when the substituent is an electron donor and from unrearranged 6endo-R-substituted cations when the substituent is an electron acceptor.

Carbon Participation in the Solvolysis of 6-exo-substituted 2-exo- and 2-endo-Norbornyl p-Toluenesulfonates. Norbornanes Part 5

The solvolysis rates and products of the 6-exo-substituted 2-exo- 1a-1u, and 2-endo-norbornyl p-toluenesulfonates 2a-2u, have been determined.In general, the rate constants for 1 and 2 (log k) correlate well with the inductive constants ?qI of the substituents at C(6); however, their sensitivity to ?qI is much larger in the 2-exo-series 1 than in the 2-endo-series 2.This differential transmission of polar effects is the cause of decreasing 2-exo/2-endo rate ratios from 2388 for R=t-C4H9 to 0.37 for R=Br, i.e., with increasing electron attraction by the substituent.The high sensitivity of the rate constants for the 2-exo-p-toluenesulfonates 1 to ?qI indicates an unusually strong inductive interaction between C(6) and the incipient cationic center at C(2).This interaction is ascribed to the participation of the pentacoordinate C(6)-atom, i.e. to 1,3-bridging, a consequence of steric hindrance of nucleophilic solvent participation in norbornanes.Donor substituents enhanche 1,3-bridging, lead to faster reactions and to the formation of 2-exo substitution products.Conversely, acceptor substituents reduce 1,3-bridging, decrease rates and facilitate the formation of 2-endo substitution products.Graded 1,3-bridging is discussed in the light of Winstein's nonclassical ion concept.

EPIMERIC 2-NORBORNYL CATIONS IN THE SOLVOLYSIS OF 6-exo- AND 6-endo-SUBSTITUTED 2-exo-NORBORNYL p-TOLUENESULFONATES

Solvolysis of 6-exo- and 6-endo-substituted 2-exo-norbornyl tosylates 1 and 3, respectively, yields identical or different product mixtures depending on the inductive effect of the substituent, indicating that induction involves graded ?-participation.

Carbon Participation in the Solvolysis of 6-endo-substituted 2-exo-Norbornyl Toluenesulfonates. Norbornanes Part 6

The solvolysis rate constants k for the 6-endo-substituted 2-exo-norbornyl toluenesulfonates 7 have been determined.Values of logk correlate well with the respective inductive constants of the substituents except when the latter are nucleophilic and therefore lead to endo-cyclization, or when they are n-electron donors and cause concerted fragmentation.In general 6-endo-substituted tosylates 7 react somewhat more slowly than their 6-exo-epimers. Identical or different mixtures were obtained from the C(6)-epimers 7 and 1 depending on whether the substituent was an electron donor or acceptor.It is concluded that donor substituents at C(6) enhance 1,3-bridging in the intermediate epimeric cations and lead to their rapid and complete equilibration, and that electron acceptors reduce bridging and hence their equilibration rates.

POLAR AND ANCHIMERIC EFFECTS IN THE SOLVOLYSIS OF 6-endo-SUBSTITUTED 2-NORBORNYL-p-TOLUENE-SULFONATES

A study of the influence of 6-endo substituents on the reactivity of 2-exo- and 2-endo-norbornyl p-toluenesulfonates 3 and 4, respectively, confirms that polar rather than steric effects control relative rates.

Die Hydrolyse von 6exo-substituierten 2exo- und 2endo-Norbornylestern der p-Toluolsulfonsaeure

Hydrolysis of the 6exo-substituted 2exo- and 2endo-norbornyl p-toluenesulfonates 1b-l and 2b-l, respectively, in 70percent dioxane led to different amounts of the following products: Unrearranged 2exo-norbornanols 3 and norbornenes 5, accompained in somes cases by small amounts of the rearranged Rendo-epimers 4 and 6 and by nortricyclenes 7.When the 6exo-substituent was a nucleophile group as in 1e-l and 2e-l, various amounts of tricyclic products were also formed by endo-cyclozation.These results show that the 2exo- and 2endo-esters 1 and 2, respectively, react by way of different intermediates.In cases where the 6exo-substituent was an n-electron donor, as in 1m-r and 2m-r, quantitative fragmentation to (3-cyclopentenyl)acetaldehyde (13) occurred.