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The rule states that with the addition of a protic acid HX or other polar reagent to an asymmetric alkene, the acid hydrogen (H) or electropositive part gets attached to the carbon with more hydrogen substituents, and the halide (X) group or electronegative part gets attached to the carbon with more alkyl substituents. This is in contrast to ...
In atomic physics, a partial charge (or net atomic charge) is a non-integer charge value when measured in elementary charge units. It is represented by the Greek lowercase delta (𝛿), namely 𝛿− or 𝛿+. Partial charges are created due to the asymmetric distribution of electrons in chemical bonds.
The concerted reaction occurs due to the orbital overlap between the alkene and the allylic enophile. [2] The electrons in the highest occupied molecular orbital of the ene are transferred to the lowest occupied molecular orbital of the enophile. [7] Figure 1. The mechanism of the group transfer reaction is allowed by the orbital overlap of the ...
In the case of metal-alkenes and alkynes, the strengthening of the M–C 2 R 4 and M–C 2 R 2 bond is reflected in bending of the C–C–R angles which assume greater sp 3 and sp 2 character, respectively. [8] [9] Thus strong π backbonding causes a metal-alkene complex to assume the character of a metallacyclopropane. [10]
In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. [1] The double bond may be internal or in the terminal position.
There are several functional groups that contain an alkene such as vinyl group, allyl group, or acrylic group. Hydrocarbons may form charged structures: positively charged carbocations or negative carbanions. Carbocations are often named -um. Examples are tropylium and triphenylmethyl cations and the cyclopentadienyl anion.
Alkenes that are particularly amenable to asymmetric hydrogenation often feature a polar functional group adjacent to the site to be hydrogenated. In the absence of this functional group, catalysis often results in low ee's. For some unfunctionalized olefins, iridium with P,N-based ligands) have proven effective, however. Alkene substrates are ...
Two charges are present with a negative charge in the middle (red shade), and a positive charge at the ends (blue shade). In chemistry , polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment , with a negatively charged end and a positively charged end.