Silicon-functionalized silyl enol ethers. Part 2. Silyl enol ethers bearing stereogenic silicon atoms and chiral alkoxy groups: the effect of these groups upon the facial selectivity of the epoxidation of an enol double bond

1988 ◽  
Vol 53 (4) ◽  
pp. 920-923 ◽  
Author(s):  
Robert D. Walkup ◽  
Nihal U. Obeyesekere
1981 ◽  
Vol 22 (27) ◽  
pp. 2595-2598 ◽  
Author(s):  
Kiyotomi Kaneda ◽  
Nobuyoshi Kii ◽  
Koichiro Jitsukawa ◽  
Shiichiro Teranishi

2014 ◽  
Vol 18 (5) ◽  
pp. 525-546 ◽  
Author(s):  
Carmen Hernandez-Cervantes ◽  
Miriam Alvarez-Corral ◽  
Manuel Munoz-Dorado ◽  
Ignacio Rodriguez-Garcia

2019 ◽  
Vol 23 (16) ◽  
pp. 1738-1755
Author(s):  
Humaira Y. Gondal ◽  
Zain M. Cheema ◽  
Abdul R. Raza ◽  
Ahmed Abbaskhan ◽  
M. I. Chaudhary

Following numerous applications of Wittig reaction now functionalized phosphonium salts are gaining attention due to their characteristic properties and diverse reactivity. This review is focused on α-alkoxyalkyl triphenylphosphonium salts: an important class of functionalized phosphonium salts. Alkoxymethyltriphenylphosphonium salts are majorly employed in the carbon homologation of carbonyl compounds and preparation of enol ethers. Their methylene insertion strategy is extensively demonstrated in the total synthesis of a wide range of natural products and other important organic molecules. Similarly enol ethers prepared thereof are important precursors for different organic transformations like Diels-Alder reaction, Claisen rearrangement, Coupling reactions, Olefin metathesis and Nazarov cyclization. Reactivity of these α-alkoxyalkylphosphonium salts have also been studied in the nucleophilic substitution reactions. A distinctive application of this class of phosphonium salts was recently reported in the phenylation of carbonyl compounds under very mild conditions. Synthesis of structurally diverse alkoxymethyltriphenylphosphonium salts with variation in alkoxy groups as well as counter anions are reported in literature. Here we present a detailed account of different synthetic methodologies for the preparation of this unique class of quaternary phosphonium salts and their applications in organic synthesis.


2002 ◽  
Vol 67 (3) ◽  
pp. 353-364 ◽  
Author(s):  
Petr Melša ◽  
Ctibor Mazal

Diastereoselectivity of 1,3-dipolar cycloaddition reactions of benzyl azide, diazomethane, a nitrile oxide and a nitrile imine to α-methylidene-γ-lactone dipolarophile was effectively controlled by a bulky γ-substituent, 4-methyl-2,6,7-trioxabicyclo[2.2.2]octan-1-yl in γ-position of the dipolarophile. The dipoles added from the less hindered face of the double bond with an excellent selectivity. Enantiomerically pure dipolarophile was prepared from the easily available (S)-5-oxotetrahydrohydrofuran-2-carboxylic acid.


Author(s):  
Kohsuke Aikawa ◽  
KyoKo Nozaki ◽  
Takashi Okazoe ◽  
Yuichiro Ishibashi ◽  
Akiya Adachi

ChemInform ◽  
2010 ◽  
Vol 23 (48) ◽  
pp. no-no
Author(s):  
E. C. ROOS ◽  
H. HIEMSTRA ◽  
W. N. SPECKAMP ◽  
B. KAPTEIN ◽  
J. KAMPHUIS ◽  
...  

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