... JavaScript is disabled on your browser. Please enable JavaScript to use all the features on this page. Tetrahedron Letters. Volume 49, Issue 23, 2 June 2008, Pages 3802–3804. Cover image Cover image. Thiourea catalysis of NCS in the synthesis of α-chloroketones. ... 31 March 2008, Available online 4 April 2008. Abstract. Thiourea catalyzes NCS α-chlorination of alkyl ketones to provide α-chloroketones in very high yields at exceptionally rapid reaction speeds ...