Synthesis of β-ketonitriles, α,β-alkynones and biscabinols from esters using tert-butoxide-assisted C(O)–C (i.e., acyl–C) coupling under ambient conditions

A green, economical synthesis of β-ketonitriles and trifunctionalized building blocks from esters and lactones

“…Other methods were explored in an attempt to increase product yields. Although a putative radical mechanism that may be promoted in the presence of oxygen had previously been postulated by Kim et al [10], we did not obtain increased product yields when carrying out the reaction in air. Furthermore, heating the reaction mixtures above rt when using NaH as a base in refluxing THF was clearly detrimental to product yield according to our previous observations and was not attempted.…”

“…To date, the most economically appealing conditions from an environmentally friendly perspective entail relatively mild base-promoted (potassium tert -pentoxide or potassium tert -butoxide) acylation of substituted nitrile anions with esters under ambient conditions, as published by Ji et al (2006) [9] and Kim et al (2013) [10]. The large excess of ester and expensive base (potassium tert -pentoxide) required in the former method, in our opinion rendered it less economical and practical as a scalable option.…”

Conjugated Ynones in Organic Synthesis

“…113 The synthesis of ynones from aliphatic ethyl esters has been carried out using terminal alkynes and potassium tert-butoxide as a base in THF and air at room temperature with moderate to good yields (33−76%). 114 The presence of BF 3 •OEt 2 was crucial for the alkynylation of ethyl trifluoroacetate using an alkynyllithium derived from the alkyne 123 affording ynone 124 in good yield (Scheme 30). 115 This ynone 124 has been used for the synthesis of the pyrazole herbicide fluazolate by reaction with hydrazine hydrate.…”

Electrochemical Synthesis of β‐Ketonitriles from Aryl Methyl Ketones

“…Later, an efficient electrochemical protocol for the α ‐CH thiocyanation and sulfenylation of ketones was repored . These protocols suffer from some flaws such as using transition metals, unconventional additives, high temperatures, and employing strong base . Herein, we report a synthesis of β ‐ketonitriles by cyanation of aryl methyl ketones with two efficient paths under catalyst‐ and oxidant‐free electrochemical anodic oxidation conditions with Me 3 SiCN (TMSCN), as a non‐hyper toxic source of cyanide, and KCN (Scheme ).…”