169888-86-2Relevant academic research and scientific papers
Cyclization Reactions of Oxyallyl Cation. A Method for Cyclopentane Ring Formation
Vulovic, Bojan,Trmcic, Milena,Matovic, Radomir,Saicic, Radomir N.
, p. 9618 - 9621 (2019/12/24)
Unsaturated oxyallyl cations with a suitably positioned alkene bond undergo 5-exo-cyclization with the formation of vinylcyclopentane derivatives. Alkyne analogues provide allenes. The reaction proceeds with a moderate to excellent level of stereoselectiv
Synthesis of biaryl compounds using tandem ruthenium-catalyzed ring-closing metathesis
Yoshida, Kazuhiro,Shida, Hiroaki,Takahashi, Hidetoshi,Yanagisawa, Akira
supporting information; experimental part, p. 344 - 349 (2011/02/27)
Tandem ring-closing enyne metathesis (RCEM)/ring-closing olefin metathesis (RCM) of tetraenynes with Grubbs second-generation catalyst, followed by elimination, was found to be a new and efficient synthetic approach to biaryl compounds. A preliminary asymmetric version of this approach, which used homochiral Ru-alkylidene catalysts, is also presented. A ringing endorsement: Tandem ring-closing enyne metathesis (RCEM)/ring-closing olefin metathesis (RCM) of tetraenynes with the Grubbs second-generation catalyst followed by elimination, was found to be a new and efficient synthetic approach to biaryl compounds (see scheme). A preliminary asymmetric version of this approach is also presented.
Phenylsulfonyl ene-allenes as efficient precursors to bicyclic systems via intramolecular [2 + 2]-cycloaddition reactions
Padwa, Albert,Lipka, Helmut,Watterson, Scott H.,Murphree, S. Shaun
, p. 6238 - 6250 (2007/10/03)
Various phenylsulfonyl allene derivatives were prepared with double bonds tethered either to the α-position or the γ-position of the allene. These substrates underwent a highly regio- and stereospecific thermal [2 + 2]-cycloaddition across the nonactivated cumulene double bond, forming distal cycloadducts (i.e., 57) in the case of α-tethered allenes and proximal adducts (i.e., 25) in the case of γ-tethered allenes. The mechanistic rationale for the observed stereospecificity involves initial diradical formation, followed by a rapid ring closure to the more stable cis-fused ring system. The tether may be equipped with heteroatoms, allowing for the formation of fused heterocycles (e.g., 61), and the cycloaddition can be facilitated by the introduction of sterically bulky groups and/or by conformational rigidity to the tether. Other modes of cyclization were observed in the presence of sodium benzenesulfinate or Lewis acids, in which cases polar mechanisms prevail. The chemoselectivity is reversed for [4 + 2]-cycloadditions, which prefer instead to engage the vinyl sulfone moiety, independent of whether the tether is attached to the α- or γ-position of the allene.
