A Robust and General Protocol for the Lewis‐Base‐Catalysed Reaction of Alcohols and Alkyl Propiolates

Abstract

A general and practical protocol for the tertiary‐amine‐catalysed synthesis of β‐alkoxyacrylates from primary, secondary, and tertiary alcohols is described. Of the currently used catalysts, DABCO proved to be the best one for this process. Three factors seem to influence the outcome of the reaction: (1) the nucleophilic strength of the catalyst, (2) the electrophilicity of the intermediate ammonium acrylate, and (3) the pKa/nucleophilicity of the alcohol/alkoxide nucleophile. Reactivity tuning enables the transformation of a range of tertiary alcohols into the corresponding β‐alkoxyacrylate derivatives. Differences in the reactivity of different types of alcohol allow the selective transformation of diols containing two different hydroxy groups into the corresponding monoprotected derivatives. This protocol will aid other synthetic organic chemists to easily prepare such vinyl ethers under atom‐economic, efficient, and bench‐friendly reaction conditions.

Organocatalyzed Glycosylation Reactions of Carbohydrates

“…The same high diastereoselectivities and high E/Z-ratios were detected in both series, using D-ribose 29 as The intermolecular addition of alcohols to terminal and activated alkynes has been reported before [133][134][135][136][137][138] and has been used extensively in radical cyclization of β-alkoxyacrylates [139][140][141][142][143][144][145][146][147][148][149][150][151][152][153][154], in reductive cyclizations of β-alkoxyacrylates (Maitotoxin total synthesis [155][156][157][158][159]) and palladium-catalyzed cyclization in the presence of CO [160]. For an overview of the application of alkynes in organocatalysis see reference [161].…”

Microwave‐Assisted Organocatalyzed Rearrangement of Propargyl Vinyl Ethers to Salicylaldehyde Derivatives: An Experimental and Theoretical Study

“…These PVEs were convenientlyp repared from the corresponding tertiaryp ropargyla lcohols and methyl propiolate according to our recently reported protocol. [24] In general,t ertiaryP VEs proved to be excellent substrates for this catalytic reaction affording the corresponding aromatic derivatives in good average yield. The PVEs 1a-d [23] derived from acyclic ketonesd elivered the corresponding aromatic derivatives 14 a-d in good average yield and incorporated varied substitution patternsa tt he aromaticr ing, including alkyl, aryl, and oxygen-containing substituents.…”

Organocatalytic transformations of alkynals, alkynones, propriolates, and related electron-deficient alkynes

“…70 Very recently, Tejedor and co-workers have described an efficient, robust, and general method for the addition of primary, secondary, and tertiary alcohols to give b-alkoxyacrylates using DABCO as the catalyst. 71 In 2005 Yavari and co-workers described the Michael addition of phenols 140 to alkyl propiolates 105 in the presence of stoichiometric amount of triphenylphosphine 80. 72 The reaction can lead either to a mixture of two isomers (141 or 142) or only one regioisomer, depending on the substituents present, their position at the aromatic ring and the aromatic ring structure (Table 2).…”