138964-29-1Relevant academic research and scientific papers
Borrowing hydrogen: Indirect "Wittig" olefination for the formation of C-C bonds from alcohols
Black, Phillip J.,Edwards, Michael G.,Williams, Jonathan M. J.
, p. 4367 - 4378 (2007/10/03)
The successful development of an indirect three-step domino sequence for the formation of C-C bonds from alcohol substrates is described. An iridium-catalysed dehydrogenation of alcohol 1 affords the intermediate aldehyde 2. The desired C-C bond can then be formed by a facile Wittig olefination, yielding the intermediate alkene 3. In the final step the alkene is hydrogenated to afford the indirect Wittig product, the alkane 4. The key to this process is the concept of borrowing hydrogen; hydrogen removed in the initial dehydrogenation step is simply borrowed by the iridium catalyst. Functioning as a hydrogen reservoir, the catalyst facilitates C-C bond formation before subsequently returning the borrowed hydrogen in the final step. Herein we present full details of our examination into both the substrate and reaction scope and the limitations of the catalytic cycle. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Catalytic electronic activation: Indirect "Wittig" reaction of alcohols
Edwards, Michael G.,Williams, Jonathan M.J.
, p. 4740 - 4743 (2007/10/03)
Hydrogen atoms are borrowed during the in situ oxidation of the starting alcohol to the corresponding aldehyde and are subsequently returned in the hydrogenation of the alkene intermediate, which is formed by Wittig olefination of the aldehyde. This proce
Ring-opening reactions of 4-aryl-3,4-dihydro-1,5-benzodioxepin-2-ones: implication of lithium diisopropylamide in Cannizzaro-type transformation
Gelebe, Aifheli C.,Kaye, Perry T.
, p. 26 - 28 (2007/10/03)
4-Phenyl-3,4-dihydro-1,5-benzodioxepin-2-one, on treatment with lithium diisopropylamide (LDA), undergoes fission of the heterocyclic ring to afford catechol monocinnamate.Similar reaction in the presence of certain aldehydes, however , results in double fission of the heterocyclic ring, yielding cinnamate esters.
Chemistry of Silylketenes: a Simple Preparation of α-Silyl-α-stannylacetic Esters and Their Stereoselective Reformatsky-type Reaction with Aldehydes or Aldimines
Akai, Shuji,Tsuzuki, Yasunori,Matsuda, Satoshi,Kitagaki, Shinji,Kita, Yasuyuki
, p. 2813 - 2820 (2007/10/02)
Silylketenes 1a, b reacted smoothly with alkoxystannanes 3 to give the corresponding α-silyl-α-stannylacetates 4 almost quantitatively.Treatment of 4 with TiCl4 caused selective cleavage of the C-Sn bond to bring about Reformatsky-type reaction with aldehydes 6 giving β-hydroxy-α-silyl esters 7.These two steps were carried out by one-pot operation, and variously substituted compounds 7 were obtained with high syn-selectivity (52-96percent d.e.) in 41-89percent yields.A similar one-pot procedure starting from 1a-c, 3, and aldimines 11 also provided the corresponding β-amino-α-silyl esters 12 with excellent syn-selectivity (96percent d.e. ) in 64-94percent yields.Stereocontrolled preparation of both (E)- and (Z)-α,β-unsaturated esters 8 and a syn-amino diol derivative 17 from syn-7 and syn-12, respectively, is also described.
