Organocatalytic Asymmetric Vinylogous Michael Reactions

Abstract

Since R. C. Fuson formulated the principle of vinylogy, this platform has been extensively developed through combining diverse predominant chemical transformations. Among them, asymmetric vinylogous Michael reaction has been recognized as an efficient method to build chiral 1,7‐dioxo C chains (1,9‐dioxo C chains for bisvinylogous manifold) with diverse functional groups, which provides robust approaches to access numerous chiral compounds with pharmaceutical importance. In this review, the advances in the area of organocatalytic asymmetric vinylogous Michael reactions on the period from 2014 to nowadays are discussed, including the current scope, limitations of the transformations and applications in asymmetric synthesis of complex and valuable compounds.

Catalytic Asymmetric Mannich‐Type Reaction Enabled by Efficient Dienolization of α,β‐Unsaturated Pyrazoleamides†

“…Compared to the intensive research on enolization of carbonyl compounds, the dienolization of linear α,β‐unsaturated compounds is much less investigated except for some special substrates. [ 6‐11 ] Utilization of these dienolates in organic synthesis would result in synthetically powerful vinylogous reaction. [ 6‐11 ] Generally speaking, the dienolization of linear α,β‐unsaturated ketones, esters, and amides is very challenging in the presence of a common organic base due to the high p K a value of the γ‐protons.…”

“…[ 6‐11 ] Utilization of these dienolates in organic synthesis would result in synthetically powerful vinylogous reaction. [ 6‐11 ] Generally speaking, the dienolization of linear α,β‐unsaturated ketones, esters, and amides is very challenging in the presence of a common organic base due to the high p K a value of the γ‐protons. Therefore, linear β,γ‐unsaturated compounds are employed in asymmetric catalysis to facilitate the generation of the corresponding dienolates by means of the relatively low p K a value of α‐protons (Scheme 1a).…”

The Vinylogous Michael Addition of 3‐Alkylidene‐2‐oxindoles to β,γ‐Unsaturated α‐Keto Esters by Bifunctional Cinchona Alkaloids

“…Over the last few years, research involving catalytic asymmetric direct vinylogous reactions have been growing rapidly A variety of vinylogous pronucleophiles such as butenolides, butyrolactams, coumarins, allyl alkyl/aryl ketones, 5‐alkyl‐4‐nitroisoxazoles, 3‐alkylidene oxindoles, α‐alkyl/arylidene pyrazolinones, 2‐allylazaarenes, β,γ‐unsaturated amides and esters, oxazole‐2‐thiones, N ‐2,2,2‐trifluoroethyl isatin ketimines, enals and enones, nitrones, and α,α‐dicyanoalkenes (Scheme ). have been explored for direct vinylogous Michael reaction.…”

Computational exploration of copper catalyzed vinylogous aerobic oxidation of unsaturated compounds

“…One particular class of selective oxidation reactions achieved by a combined use of air as an oxidant and copper as a catalyst is highly desirable due to the natural abundance of air and copper [4][5][6] . Over the past few decades, great progress has been made in this field and many successful Cu-catalyzed aerobic reactions have been developed [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] .Catalytic vinylogous reactions are among the most important reactions in organic synthesis due to their extensive application in the synthesis of complex natural products and bioactive molecules [24][25][26][27] . Despite significant advances in transition metal-catalyzed α-or β-functionalization of α,β-and β,γ-unsaturated compounds [28][29][30][31][32] , the vinylogous version leading to synthetically valuable γ-substituted α,β-unsaturated compounds [33][34][35][36] has been rarely studied.…”