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The Cram's rule of asymmetric induction named after Donald J. Cram states In certain non-catalytic reactions that diastereomer will predominate, which could be formed by the approach of the entering group from the least hindered side when the rotational conformation of the C-C bond is such that the double bond is flanked by the two least bulky groups attached to the adjacent asymmetric center. [3]
In organic chemistry, a group transfer reaction is a class of the pericyclic reaction where one or more groups of atoms is transferred from one molecule to another. Group transfer reactions can sometimes be difficult to identify when separate reactant molecules combine into a single product molecule (like in the ene reaction).
While utilizing the R-group as the core results in similar structures found using ATRP or NMP, the ability to use the Z-group as the core makes RAFT unique. When the Z-group is used, the reactive polymeric arms are detached from the star's core during growth and to undergo chain transfer, must once again react at the core. [18]
Example cheletropic reactions: Case 1: the single atom is the carbonyl carbon (C=O) that ends up in carbon monoxide (C≡O). Case 2: the single atom is the nitrogen atom in the diazenyl group (N=N), which ends up as dinitrogen (N≡N). The above are known as cheletropic eliminations because a small, stable molecule is given off in the reaction. [1]
In chemistry, transferability is the assumption that a chemical property that is associated with an atom or a functional group in a molecule will have a similar (but not identical) value in a variety of different circumstances. [1] Examples of transferable properties include: Electronegativity; Nucleophilicity; Chemical shifts in NMR spectroscopy
Enantioselective synthesis, also called asymmetric synthesis, [1] is a form of chemical synthesis.It is defined by IUPAC as "a chemical reaction (or reaction sequence) in which one or more new elements of chirality are formed in a substrate molecule and which produces the stereoisomeric (enantiomeric or diastereomeric) products in unequal amounts."
E (from the German entgegen) means "opposed" in the sense of "opposite". That is, Z has the higher-priority groups cis to each other and E has the higher-priority groups trans to each other. Whether a molecular configuration is designated E or Z is determined by the CIP rules; higher atomic numbers are given higher priority. For each of the two ...
In the context of electron transfer, these groups enhance the oxidizing power tendency of the attached species. For example, Tetracyanoethylene serves as an oxidant due to its attachment to four cyano substituents, which are electron-withdrawing groups. [5] Oxidants with EWGs are stronger than the parent compound.