Chemoselective Reactions of Anthrone with α,β-Unsaturated Ketones

Abstract

In the presence of ZnCl 2 , 1,4-conjugated addition of anthrone with ,-unsaturated ketones proceeded to give mono-Michael adducts, whereas in basic solution it gave bis-Michael adducts.

Benzylic Functionalization of Anthrones via the Asymmetric Ring Opening of Oxabicycles Utilizing a Fourth‐Generation Rhodium Catalytic System

“…Moreover, a survey of the literature revealed a paucity of transition metal catalyzed protocols to functionalize the benzylic position of anthrones. Examples include zinc catalyzed protocols for 1,4‐addition or Diels‐Alder reactions on acrylic substrates,7b–c as well as a ruthenium catalyzed dialkylation of anthrones with methyl vinyl ketone 7a. The above mentioned examples are the sole transition metal catalyzed examples known in literature, where enantioselective functionalization was not possible.…”

“…As ubsequent solvents creen provided us with evidencef or solvente ffects (Table 1, entries [6][7][8][9]. While THF has been traditionally used in most Rh-catalyzed ARO systemst od ate, it appears that switching solvents have ap rofound effect on the regioselectivity of this protocol.…”

Acid-catalyzed conjugate additions to 3-fluorobutenone

“…The results show that 3-fluorobutenone (2) is effective in the acid-catalyzed Michael reaction and that its reactivity is little influenced by the fluorine atom in comparison with 1.…”

Absolute Configuration Determination and Convenient Asymmetric Synthesis ofcis‐3‐(9‐Anthryl)cyclohexanol with Proline as a Catalyst

“…Indeed, asymmetric [4 + 2] cycloadditions of 2 to N ‐substituted maleimides catalyzed by chiral Brönsted bases have been reported . However, with α , β ‐unsaturated esters, ketones and nitro compounds conjugate addition of 2 is the preferred mode of reaction . Asymmetric additions of 2 to α , β ‐unsaturated aldehydes catalyzed by a derivative of prolinol and to enones using a thiourea derivative of 9‐amino‐9‐deoxyepiquinine as a catalyst have been recently disclosed.…”