- Synthesis and use of new substituted 1,3,5-hexatrienes in studying thermally induced 6π-electrocyclizations
-
An acyclic, two heterocyclic, and two bicyclic alkenylstannanes, 3, 4a, 4b, 8 and 11, respectively, were synthesized in yields ranging from 43 to 97 %, and each was subjected to a sequence of Stille and Heck couplings with 2-bromocyclohexenyl triflate (13
- Suennemann, Hans Wolf,Banwell, Martin G.,De Meijere, Armin
-
p. 3879 - 3893
(2008/02/13)
-
- Bulky trialkylsilyl acetylenes in the Cadiot-Chodkiewicz cross-coupling reaction
-
Bulky trialkylsilyl-protected alkynes such as triethylsilyl (TES), tert-butyldimethylsilyl (TBS), and tri-isopropylsilyl (TIPS) acetylenes underwent the Cadiot-Chodkiewicz cross-coupling reaction with different bromoalkynes to form a variety of synthetically useful unsymmetrical diynes in good yields. The diyne alcohol 10 was transformed regio- and stereoselectively into enynes by hydrotelluration, carbometalation, and reduction reactions.
- Marino, Joseph P.,Nguyen, Hanh Nho
-
p. 6841 - 6844
(2007/10/03)
-
- Synthesis of 4-Silylcyclobut-2-enethiones and Their Use in Cyclobutadiene Generation
-
Alkynyl silyl sulfides 2 reacted with ynamines 3 to give 1:1 adducts.The structure of 4-silylcyclobut-2-enethiones 4 was confirmed by X-ray analysis of 4a.A cyclobutadiene intermediate is probably not involved in this reaction; we think that it is initiat
- Mueller, Martin,Foerster, Wolf-Ruediger,Holst, Andreas,Kingama, Arend J.,Schaumann, Ernst,Adiwidjaja, Gunadi
-
p. 949 - 956
(2007/10/03)
-
- THE STEREOCHEMISTRY OF ORGANOMETALLIC COMPOUNDS. XXXVI. REGIO- AND STEREO-CHEMICAL CONTROL IN THE NICKEL-CATALYSED HYDROCYANATION OF SILYLALKYNES
-
The regioselectivity of hydrocyanation of silylalkynes can be controlled by varying the size of the groups attached to silicon leading, for example, to efficient preparations of E-3-trialkylsilyl-2-alkyl-2-alkenenitriles.High yields of the silylalkene nitriles can be obtained by using either acetone cyanohydrin or hydrogen cyanide as reagents.
- Fitzmaurice, Neil J.,Jackson, W. Roy,Perlmutter, Patrick
-
p. 375 - 382
(2007/10/02)
-
- Thioketene Syntheses, VII. Substituent Effects on the Thio-Claisen Rearrangement of Alkynyl Allyl Sulfides
-
Electron acceptors in the position 2 of the allyl residues in alkynyl allyl sulfides 4, 11, 15 favor the Thio-Claisen rearrangement to give thioketenes 5, 12, 16, but in position 3 impede the reaction.For the substituent on the triple bond, the sequence silyl > alkyl > alkylthio is valid.The results can be understood in terms of a zwitterionic intermediate 19 or a highly polarized transition state of the rearrangement.
- Schaumann, Ernst,Lindstaedt, Joerg
-
p. 1728 - 1738
(2007/10/02)
-