An atom-economic and odorless thia-Michael addition in a deep eutectic solvent
摘要:
The first 100% atom-efficient and odorless protocol for carbon-sulfur bond formation in a deep eutectic solvent (DES) as both the reaction medium and catalyst is reported. The biodegradable and inexpensive DES provides an efficient and convenient ionic reaction medium for the thia-Michael addition with in situ generation of S-alkylisothiouronium salts in place of thiols without the urea by-product segment. This protocol offers several advantages including short reaction times, high yields, clean reactions, and inexpensive and commercially available starting materials. (C) 2014 Elsevier Ltd. All rights reserved.
Novel atom-economic reaction: comprehensive utilization of S-alkylisothiouronium salt in the synthesis of thioethers and guanidinium salts
作者:Pengchao Gao、Penglin Leng、Qi Sun、Xin Wang、Zemei Ge、Runtao Li
DOI:10.1039/c3ra42503g
日期:——
A novel atom-economic three-component one-pot reaction of a primary amine, an S-alkylisothiouronium salt and a Michael receptor is reported, which affords a guanidinium salt and thioether simultaneously. The guanidine moiety is involved in catalyzing the conjugated Michael addition of the mercaptan. The reaction proceeds under ambient conditions using a non-toxic EtOH–H2O mixture as the solvent, and the two products can be very easily purified. Complete atom economy is achieved by fully utilizing the S-alkylisothiouronium salt and converting the previously wasted mercaptan by-product into the valuable thioether.
Coating varnish composition and antifouling coating composition
申请人:Hitachi Chemical Co., Ltd.
公开号:EP0711813A2
公开(公告)日:1996-05-15
A coating varnish composition comprising a biodegradable polymer (A) comprising one or more kinds of constituent units (b) represented by the general formula (I), (II) or (III) and one or more other kinds of constituent units (a) capable of imparting bio-degradability:
wherein in the formula (I), R¹ and R are independently a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, an ethyl group or a phenyl group; in the formula (II), R³ and R⁴ are independently a hydrogen atom, a chlorine atom, a bromine atom, or a substituted or unsubstituted methyl or ethyl group; in the formula (III), R⁵ and R⁶ are independently a hydrogen atom, a methyl group or an ethyl group, and R⁷ is a straight, branched or cyclic alkyl group, an aryl group, a heterocyclic group or an aralkyl group, which may have one or more substituents.
rhodium-catalyzed 3-component conjunctive diastereo- and regioselective arylamidation of (homo)allylic sulfides, organon boronic acids, and dioxazolones is reported. These reactions deliver the 1,2-insertion and 2,1-insertion arylamidation products, respectively, for allylic sulfides and homoallylic sulfides. The enantioselective arylamidation of terminal and internal allylic sulfides is achieved, furnishing