Catalyst-Free Conjugated Addition of Thiols to α,β-Unsaturated Carbonyl Compounds in Water
作者:Gopal L. Khatik、Raj Kumar、Asit K. Chakraborti
DOI:10.1021/ol060846t
日期:2006.5.1
[reaction: see text] Catalyst-free conjugateaddition of thiols to alpha,beta-unsaturated carbonylcompounds in water is reported. beta-Sulfido carbonylcompounds were formed at room temperature, in short times and with excellent chemoselectivity. Competitive dithiane/dithiolane formation, transesterification, and ester cleavage were not observed. Water played a dual role in simultaneously activating
Fluoroboric acid adsorbed on silica-gel (HBF4–SiO2) as a new, highly efficient and reusable heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds
作者:Gaurav Sharma、Raj Kumar、Asit K. Chakraborti
DOI:10.1016/j.tetlet.2008.04.144
日期:2008.6
found to be a new and highly efficient heterogeneouscatalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds under solvent-free conditions. In the case of 1,3-diaryl-2-propenones, the reactions are best carried out in MeOH. The rate of thia-Michael addition was dependent on the steric hindrance at the β-carbon of the α,β-unsaturated carbonyl substrate as well as surrounding the thiol
Scope and limitations of HClO4–SiO2 as an extremely efficient, inexpensive, and reusable catalyst for chemoselective carbon–sulfur bond formation
作者:Gopal L. Khatik、Gaurav Sharma、Raj Kumar、Asit K. Chakraborti
DOI:10.1016/j.tet.2006.11.050
日期:2007.1
cyclic and acyclic α,β-unsaturatedketones afforded excellent yields of the corresponding β-sulfidocarbonyls after 2 min to 2 h. In the case of dithiols, the bis-thia-Michael adducts were formed. The rate of the reaction was found to be dependent on the electronic and steric factors of the α,β-unsaturatedketones and the thiols. A substituent at the β-carbon of the α,β-unsaturatedketone offered steric
H<sub>3</sub>PW<sub>12</sub>O<sub>40</sub>as a Useful Recyclable Heterogeneous Catalyst for the Facile and Highly Efficient Michael Addition Reaction of Thiols to α,β-Unsaturated Ketones
作者:Habib Firouzabadi、Nasser Iranpoor、Abbas Ali Jafari
DOI:10.1055/s-2004-837212
日期:——
Solid H 3 PW 1 2 O 4 0 is easily used as a heterogeneous, reusable and efficient catalyst (1 mol%) for the selective addition of thiols and dithiols to α,β-unsaturated ketones in MeCN to afford the corresponding Michael adducts in excellent yields at room temperature.
固体 H 3 PW 1 2 O 4 0 很容易用作多相、可重复使用和高效的催化剂 (1 mol%),用于将硫醇和二硫醇选择性加成到 MeCN 中的 α,β-不饱和酮,以优异的性能提供相应的迈克尔加合物在室温下产生。
Conjugate addition of indoles and thiols with electron-deficient olefins catalyzed by Bi(OTf)3
作者:M.Mujahid Alam、Ravi Varala、Srinivas R. Adapa
DOI:10.1016/s0040-4039(03)01089-x
日期:2003.6
Conjugateaddition of indoles and thiols with a variety of electron-deficient olefins mediated by a catalytic amount of Bi(OTf)3 at ambient temperature to afford the corresponding Michael adducts in good to excellent yields with high selectivity is reported.