C−C Bond Formation of Benzyl Alcohols and Alkynes Using a Catalytic Amount of KOtBu: Unusual Regioselectivity through a Radical Mechanism. Issue 11 (7th February 2019)

• Record Type: Journal Article
• Authors: Kumar, Amit; Janes, Trevor; Chakraborty, Subrata; Daw, Prosenjit; von Wolff, Niklas; Carmieli, Raanan; Diskin‐Posner, Yael; Milstein, David
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 11(2019)
• Page Start: 3373
• Page End: 3377
• Publication Date: 2019-02-07
• Subjects: alkynes -- benzyl alcohols -- potassium tert-butoxide -- radicals -- α-alkylated ketones; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201812687
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: We report a C−C bond‐forming reaction between benzyl alcohols and alkynes in the presence of a catalytic amount of KO t Bu to form α‐alkylated ketones in which the C=O group is located on the side derived from the alcohol. The reaction proceeds under thermal conditions (125 °C) and produces no waste, making the reaction highly atom efficient, environmentally benign, and sustainable. Based on our mechanistic investigations, we propose that the reaction proceeds through radical pathways. Abstract : Waste not, want not : Benzyl alcohols underwent C−C bond formation with alkynes under thermal conditions in the presence of a catalytic amount of KO t Bu to provide α‐alkylated ketones with 100 % atom economy (see scheme). The reaction showed unusual regioselectivity to give products in which the C=O group was located on the side of the molecule derived from the alcohol.