Chemistry is an experimental science, Quality Control of (R)-3-Carboxy-2-hydroxy-N,N,N-trimethylpropan-1-aminium chloride, and the best way to enjoy it and learn about it is performing experiments.Introducing a new discovery about 6645-46-1, Name is (R)-3-Carboxy-2-hydroxy-N,N,N-trimethylpropan-1-aminium chloride, molecular formula is C7H16ClNO3, belongs to chiral-catalyst compound. In a document, author is Wang, Min.
The reaction mechanism and origin of asymmetric induction in inverse electron demand Diels-Alder (IEDDA) reaction of ortho-quinone methide (o-QM) and fulvene mediated by chiral N,N’-dioxide-Sc(III) catalyst were rationalized using B3LYP-D3(BJ) functional with def2-TZVP basis set. The uncatalyzed IEDDA reaction was concerted but highly asynchronous with activation barriers of 29.8 similar to 31.8 kcal mol(-1). Good linear relationship between the Hammett substituent constant (sigma(P)) of o-QM and the activation barrier (Delta G(not equal)) of DA reaction was discovered. The secondary orbital interaction (SOI) between the conjugated diene of o-QM and fulvene moiety stabilized the endo-transition state, contributing to high endo-selectivity. The catalytic asymmetric IEDDA reaction occurred via a stepwise mechanism, including the construction of C-beta-C-4 bond, followed by the formation of C-alpha-O-1 bond. The bulky substituents (i.e., adamantyl or triphenylmethyl) in amide moiety of ligand furnished sufficient steric shielding for re-face of diene, inducing the attack of fulvene from si-face in endo-pathway. The substituent at exocyclic methylene of the unsymmetrical fulvene was crucial for the adjustment of E/Z selectivity. The steric repulsion between cyclohexyl group in fulvene and aromatic ring in o-QM raised the destabilizing strain energy (Delta E-strain) at the transition state in Z-configuration, contributing to the predominant E-product.
Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law. In my other articles, you can also check out more blogs about 6645-46-1. Quality Control of (R)-3-Carboxy-2-hydroxy-N,N,N-trimethylpropan-1-aminium chloride.
Reference:
Chiral Catalysts,
,Chiral catalysts – SlideShare