Convenient Procedure for the Indium-Mediated Hydroxymethylation of Active Bromo Compounds: Transformation of Ketones into α-Hydroxymethyl Nitroalkanes

Abstract

I n d i u m -M e d i a t e d H y d r o x y m e t h y l a t i o n o f A c t i v e B r o m o C o m p o u n d sAbstract: A very simple, safe and powerful method for the hydroxymethylation of 2-bromoesters and lactones under anhydrous conditions that avoids the use of gaseous formaldehyde is described. Moreover, under these conditions, bromonitroalkanes were converted into the corresponding a-monohydroxymethylated nitroalkanes, which are precursors of the corresponding a-amino acids. Considering the easy transformation of ketones into bromonitroalkanes, this represents a method for the formal synthesis of a-amino acids from ketones.

Enantioselective Chemo‐ and Biocatalysis: Partners in Retrosynthesis

“…[12c,13] In as econd possibility,d isconnection of the C a À C b bond by application of aldol and related reactions would result in 9 and 10 as starting points. [14] However,a lthough the catalytic enantioselective reduction of the particular olefin is known, the alternative aldol approach with an ester derivative is not. [15] On this basis,the use of catalytic,enantioselective C=C reductions with av ariety of transition metal catalysts would constitute the preferred route.…”

“…In the first of these, retrosynthetic application of an olefin reduction and the Baylis–Hillman transform yields formaldehyde 7 and ethyl acrylate 8 as suitable starting materials . In a second possibility, disconnection of the C α −C β bond by application of aldol and related reactions would result in 9 and 10 as starting points . However, although the catalytic enantioselective reduction of the particular olefin is known, the alternative aldol approach with an ester derivative is not .…”

Organoindium Reagents: The Preparation and Application in Organic Synthesis

“…Relatively sterically hindered substrates such as ethyl 2-bromopropanoate and ethyl 2-bromo-2-methylpropanoate worked equally well under optimized conditions, and use of the former substrate led to the desired product with a moderate diastereoselectivity of 2.5:1. Later, Soengas's group also extended the ultrasound-irradiated method to the use of paraformaldehyde and 2-bromolactones as substrates …”

Highly Selective Detection of Nerve‐Agent Simulants with BODIPY Dyes

“…The reactions between a number of ketones and hydroxylamine afforded the intermediate oximes, which were then oxidized to the corresponding bromonitroalkanes with oxone supported on wet basic alumina in the presence of potassium bromide. As a representative example, the case of cyclohexanone ( 1a ) is depicted in Scheme 7…”