Multi-Component Regio- and Diastereoselective Cobalt-catalyzed Hydrovinylation/Allylboration Reaction Sequence

Abstract

The combination of a regioselective cobalt-catalyzed 1,4-hydrovinylation and the diastereoselective allylboronation reaction leads to a wide scope of functionalized hydroxydienyl esters in a one-pot reaction in excellent yields. With catalytic amounts of base, these products are easily converted either into α,β,γ,δ-unsaturated hydroxyl esters or complex tetrasubstituted tetrahydropyrans in chemo- and diastereoselective fashions. In addition, a high-yielding four-component one-pot reaction involving an acrylate, two different and unsymmetrical 1,3-dienes, and an unsaturated aldehyde is presented.

Hydrovinylation Reactions – Atom‐Economic Transformations with Steadily Increasing Synthetic Potential

“…Accordingly, the quite sensitive product 62 could be isolated in acceptable 63 % yield as a single regioisomer (Scheme 28). [36] Moreover, when 62 was used as an intermediate and treated in situ with various aldehydes, such as isobutyraldehyde, the corresponding allylboration product 63 could be isolated in good to excellent yields and excellent diastereoselectivities. Eventually a four-component one-pot This reaction sequence illustrates that complex molecules can be assembled with a high control of chemo-and regioselectivity with two cobalt-catalysed 1,4-hydrovinylation reactions (first in a highly selective β-1 and second in a αselective 1,4-hydrovinylation).…”

The Synthesis of Ipsenol and Ipsdienol: A Review (1968–2020)

“…Zhang and co‐workers have exploited the reactivity of “boro‐isoprene synthon” 4,4,5,5‐tetramethyl‐2‐(2‐methylenebut‐3‐en‐1‐yl)‐1,3,2‐dioxaborolane ( 106 ) (Figure 3) [prepared as reported by Erver and Hilt by reacting isoprenylpotassium ( IV ) (Figure 3) with 2‐isopropoxy‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane], [91] against 3‐methylbutanal, in the presence of the BINOL‐derived chiral phosphoric acid ( R )‐TRIP, to synthesize ( S )‐ipsenol ( I ) (Scheme 38) in 60 % yield and 50.6 % ee [90] …”

Cobalt‐Catalyzed Multi‐Component Reactions: Recent Advances and Perspectives in Organic Synthesis

“…Hilt and Erver successfully demonstrated the preparation of functionalized hydroxydienyl esters in excellent yields through a cobalt-catalyzed one-pot reaction involving 1,4-hydrovinylation followed by diastereoselective allylboration (Scheme 7). [26] Eventually, α, β, γ, δ-unsaturated esters were developed through a base-initiated isomerization reaction and, tetrasubstituted tetrahydropyrans were obtained by diastereoselective Michael addition. Furthermore, an acrylate, an unsaturated aldehyde and two different unsymmetrical 1,3-dienes were used to carry out a one-pot four-component reaction which provided the reaction product in high yields.…”