Vinylethers can be protonated to generate oxocarbenium ions that react with Me3SiCN to form cyanohydrin alkylethers. Reactions that form racemic products proceed efficiently upon conversion of the vinylether to an α-chloro ether prior to cyanide addition in a pathway that proceeds through Brønsted acid-mediated chloride ionization. Enantiomerically enriched products can be accessed by directly protonating
乙烯基醚可以质子化以生成氧代碳正离子,该离子与 Me 3 SiCN反应形成氰醇烷基醚。在通过布朗斯台德酸介导的氯离子电离进行的途径中,在加入氰化物之前将乙烯基醚转化为 α-氯醚后,形成外消旋产物的反应有效进行。可以通过用手性布朗斯台德酸直接质子化乙烯基醚以形成手性离子对来获得对映体富集的产品。Me 3 SiCN 作为亲核试剂,PhOH 在不对称双分子亲核加成到氧碳鎓离子的罕见例子中作为化学计量质子源。计算研究为催化剂和氧代碳正离子之间的相互作用提供了模型。
Two Types of Cross-Coupling Reactions between Electron-Rich and Electron-Deficient Alkenes Assisted by Nucleophilic Addition Using an Organic Photoredox Catalyst
Two types of photoreactions between electronically differentiated donor and acceptor alkenes assisted by nucleophilic addition using an organic photoredox catalyst efficiently afforded 1:1 or 2:1 cross-coupling adducts. A variety of alkenes and alcohols were employed in the photoreaction. Control of the reaction pathway (i.e., the formation of the 1:1 or 2:1 adduct) was achieved by varying the concentration
The present invention is a fragrance precursor of formula I:
1
for a fragrant ketone of formula II:
2
and a fragrant ester of formula III:
3
wherein,
R
1
to R
5
represent independently H, —NO
2
, linear or branched C
1
-C
6
-alkyl, C
1
-C
6
-alkenyl, C
1
-C
6
-alkinyl or C
1
-C
4
-alkoxy,
R
1
and R
2
, R
2
and R
3
, R
3
and R
4
, and R
4
and R
5
may form together one or two aliphatic or aromatic rings,
R
6
and R
7
are independently H, linear or branched C
1
-C
6
-alkyl-, C
1
-C
6
-alkenyl, C
1
-C
6
-alkinyl, and
R
8
and R
9
are the residues of an acid R
8
-COOH and an alcohol R
9
OH respectively forming the fragrant ester of formula III. A method for providing an odor by admixing with a product a fragrance precursor as detailed above.
[EN] ENHANCED YIELD, STRUCTURAL CONTROL, AND TRANSPORT PROPERTIES OF POLYNORBORNENES FOR NATURAL GAS UPGRADING THROUGH MIZOROKI-HECK CROSS-COUPLINGS<br/>[FR] RENDEMENT DE PRODUCTION AMÉLIORÉ, MAÎTRISE DE LA STRUCTURE AMÉLIORÉE ET PROPRIÉTÉS DE TRANSPORT AMÉLIORÉES DE POLYNORBORNÈNES POUR LA VALORISATION DE GAZ NATUREL FORMÉS PAR L'INTERMÉDIAIRE DE COUPLAGES CROISÉS DE MIZOROKI-HECK
申请人:SAUDI ARABIAN OIL CO
公开号:WO2021202343A1
公开(公告)日:2021-10-07
Gas separation membranes are provided and more particularly, a series of addition-type and ROMP type polynorbornenes with substituents derived from Mizoroki-Heck reactions are provided and have particular utility as gas separation membranes for natural gas upgrading.
100 Percent solids epoxy, nitrile coating compositions and method of making same
申请人:THE STANDARD OIL COMPANY
公开号:EP0199529A2
公开(公告)日:1986-10-29
The invention relates to a process for producing the 100 percent solids epoxy nitrile coating compositions comprising:
1) forming a mixture of the epoxy resins with the epoxy nitrile monomers and curing agents,
2) applying the mixture to a substrate to form a coating, and
3) curing the coating so that in situ copolymerization of the epoxy resin and epoxy-nitrile monomer results in a multifunctional epoxy nitrile coating system.