1133-54-6Relevant articles and documents
Synthesis of β,β-disubstituted indanones via the Pd-catalyzed tandem conjugate addition/cyclization reaction of arylboronic acids with α,β-unsaturated esters
Gao, Ang,Liu, Xiu-Yan,Li, Hao,Ding, Chang-Hua,Hou, Xue-Long
, p. 9988 - 9994 (2018/05/31)
Under Pd catalysis with a newly synthesized electron-deficient heterocycle, 2-(4,5-dihydroimidazol-2-yl)- pyrimidine (as the ligand), the reaction of α,β-unsaturated esters with arylboronic acids afforded a wide range of 3,3-disubstituted indan-1-ones bearing a quaternary carbon in high yields. Mechanistic studies revealed that the reaction involves a tandem conjugate addition/1,4-Pd shift followed by a cyclization.
Steric Effects. A Study of a Rationally Designed System
Bott, Garry,Field, Leslie D.,Sternhell, Sever
, p. 5618 - 5626 (2007/10/02)
The principles for the rational design of systems suitable for the study of steric effects are defined.A suitable molecular framework was synthesized and a study of internal rotaition by dynamic NMR spectroscopy (DNMR) 0f 33 derivatives, differing principally in the nature of the molecular fragment (X), showed the following. (i) For 1 (Y = Me; X = halogen) the rotaition barriers (ΔG excit.) increase smoothly and monotonically with the van der Waals radius of X (rx), which permits the estimation of effective rx for fragments of lower symmetry. (ii) The rotational barriers are the sum of additive contributions, designated interference values (IH-X), which can be used to predict the rotational barriers in 2,2'-disubstituted biphenyls. (iii) A simple geometrical parameter, apparent overlap (r*), which is related to the distortion of the framework in the transition state, is proposed and found to have an excellent linear correlation with the barrier to rotation in 2,2'-disubstituted biphenyls. (iv) This correlation can be used for a semiquantitative estimation of rotational barriers in biaryls and other systems.
