- Carbonylation of Selenilimines to Arylsulfonyl Isocyanates
-
Selenilimines of general formula ArSO2N=SePh2, 1, can be catalytically carbonylated to arylsulfonyl isocyanates, 2, in the presence of palladium complexes as catalysts.This transformation represents a new two-step oxidative N-carbonylation reaction.
- Besenyei, Gabor,Nemeth, Sandor,Simandi, Laszlo I.
-
-
Read Online
- Intermolecular C-H Amidation of Alkenes with Carbon Monoxide and Azides via Tandem Palladium Catalysis
-
An atom- and step-economic intermolecular multi-component palladium-catalyzed C-H amidation of alkenes with carbon monoxide and organic azides has been developed for the synthesis of alkenyl amides. The reaction proceeds efficiently without an ortho -directing group on the alkene substrates. Nontoxic dinitrogen is generated as the sole by-product. Computational studies and control experiments have revealed that the reaction takes place via an unexpected mechanism by tandem palladium catalysis.
- Gu, Zheng-Yang,Wu, Yang,Jin, Feng,Bao, Xiaoguang,Xia, Ji-Bao
-
supporting information
p. 3361 - 3371
(2021/04/09)
-
- Pd-catalyzed amidation of 1,3-diketones with CO and azidesviaa nitrene intermediate
-
An efficient Pd-catalyzed amidation of 1,3-diketones has been developed using carbon monoxide and organic azides. This reaction provides a step-economic approach to produce β-ketoamides from readily available compounds under mild ligand-, oxidant-, and base-free conditions. The mechanistic studies showed that the reaction occurred through anin situgenerated isocyanate intermediate.
- Gu, Zheng-Yang,Chen, Jie,Xia, Ji-Bao
-
p. 11437 - 11440
(2020/10/12)
-
- Synthesis method of tertiary butyl isocyanate
-
The invention relates to a synthesis method of tertiary butyl isocyanate. The method comprises the following steps of mixing an inert solvent and para toluene sulfonamide, introducing phosgene at 100DEG C to 120 DEG C, feeding an inert gas for driving gas after reaction, and thus obtaining a first reaction solution; at 0 DEG C to 20 DEG C, dropwise adding tert-butylamine into the first reaction solution, heating and refluxing for 4h or more, and thus obtaining a second reaction solution; separating and purifying the second reaction solution to obtain tertiary butyl isocyanate. According to the synthesis method of tertiary butyl isocyanate, the stability and the yield of the process can be improved, and the purity of the obtained tertiary butyl isocyanate product is higher.
- -
-
Paragraph 0053-0088
(2018/09/08)
-
- Syntheses of isocyanates via amines and carbonyl fluoride
-
Isocyanates are widely used in many different areas, but the most common synthesis route-phosgene route cannot fit the more and more rigorous restriction of safety and environment. Here, a facile synthesis method of isocyanates via amines and carbonyl fluoride is proven feasibly by expanding its applications to the syntheses of nine different isocyanates. And two differences with the phosgene route are proposed. The reaction could occur under milder conditions and afford isocyanates in good yields, especially for the isocyanates containing electron withdrawing groups. It is appealing for industrial application.
- Quan, Hengdao,Zhang, Ni,Zhou, Xiaomeng,Qian, Hua,Sekiya, Akira
-
-
- Synthesis of isocyanates from carbamate esters employing boron trichloride
-
The conversion of carbamate esters to isocyanates and diisocyanates of industrial importance is possible using BCl3 in the presence of Et3N; the reaction is simple in execution and work-up, occurring under mild conditions and affording isocyanates in excellent yields.
- Butler,Alper
-
p. 2575 - 2576
(2007/10/03)
-
- Unconventional Regiospecific Syntheses of Aromatic Carbonamides and Thiocarbonamides by Means of Tin-Mediated Friedel-Crafts Reactions
-
Friedel-Crafts reactions of stannylarenes 1 with tosyl isocyanate (TsNCO, 2) give N-tosylcarbonamides 3 via ipso substitution of the stannyl group.Thus, unconventionally substituted aromatic carbonamides can be obtained.The combination of the reaction of 1 and 2 with that of 1 and chlorosulfonyl isocyanate (14) allows one-pot syntheses of N-(arylsulfonyl)-substituted aromatic carbonamides with optional substitution patterns on both aromatic rings.The known ipso-specific substitutions of stannylarenes with 14 are extended to bi- and tricyclic arenes as well as to thiophenes 6 and 22.One stannyl group can serve as a leaving group for two aromatic systems, as shown with diaryldialkyltins 29.Also, stannylalkanes such as 27 react with 14 to afford alkylsulfonyl isocyanates and products of further reactions, such as 28.From the reactions of 1 with ethoxycarbonyl isocyanate (32), ortho- and meta-substituted aromatic thiocarbonamides 33 which are potential precursors for further syntheses, are accessible.The scope, limitations, and mechanism of these electrophilic substitutions are outlined.
- Arnswald, Martin,Neumann, Wilhelm P.
-
p. 7022 - 7028
(2007/10/02)
-
- Palladium-catalyzed carbonylation of (arylsulfonyliminoido)-benzenes to arylsulfonyl isocyanates
-
In the presence of palladium complexes as catalysts, carbonylation of (arylsulfonyliminoiodo)benzenes to arylsulfonyl isocyanates can be accomplished with 50-80% yield.
- Besenyei,Simandi
-
p. 2839 - 2842
(2007/10/02)
-
- Mild and Efficient Synthesis of Aromatic Sulfonamides by in situ Preparation of the Corresponding Sulfonyl Isothiocyanates
-
A new reaction between chlorosulfonyl isocyanate (1) and trialkylstannyl-substituted arenes 2a-k, 7, 9 is described.It provides the aromatic sulfonyl isocyanates 3 or their derivatives, the sulfonamides 4a-j, the sulfonylcarbamates 5a-b, or sulfonylureas 6, respectively.The trialkylstannyl group as an efficient leaving group allows mild reaction conditions to be applied and unusual substitution patterns to be obtained, normally not accessible by electrophilic aromatic substitutions.Thus, sulfonamidation can be achieved in meta position to a trifluoromethyl group. Key words: Electrophilic aromatic substitution; sulfodestannalytion; isocyanates, sulfonyl, aromatic; sulfonyl compounds; trialkylarylstannanes, application of
- Arnswald, Martin,Neumann, Wilhelm P.
-
p. 1997 - 2000
(2007/10/02)
-
