Indium mediated allylation and propargylation reactions of dimethyl acetals and ketals
作者:Jin Sun Kwon、Ae Nim Pae、Kyung Il Choi、Hun Yeong Koh、Youseung Kim、Yong Seo Cho
DOI:10.1016/s0040-4039(01)00042-9
日期:2001.3
Indium mediated allylation and propargylation reactions of acetals and ketals with various allyl or propargyl bromides in aqueousmedia successfully provided the corresponding homoallylic or homopropargylic (and allenylic) alcohol, respectively, in moderate to good yields. Highly chemoselectiveallylation is also described. The ketal and aryl acetal could be selectively allylated over the aliphatic
Allyl-, Allenyl-, and Propargyl-Transfer Reactions through Cleavage of CC Bonds Catalyzed by an N-Heterocyclic Carbene/Copper Complex: Synthesis of Multisubstituted Pyrroles
作者:Masahiro Sai、Hideki Yorimitsu、Koichiro Oshima
DOI:10.1002/anie.201100631
日期:2011.3.28
Cat. in the bag: The pictured copper complex can promote CC bond cleavage through retro‐allylation of homoallyl alcohols to form allylcopper species. This process is applicable to catalytic allylation of aldehydes and imines with homoallyl alcohols. The method has also been extended to regioselective allenylation and propargylation of imines.
Pd(0) catalyzed intramolecular Heck reaction: a versatile route for the synthesis of 2-aryl substituted 5-, 6-, and 7-membered O-containing heterocycles
作者:Shubhankar Samanta、Hemakesh Mohapatra、Rathin Jana、Jayanta K. Ray
DOI:10.1016/j.tetlet.2008.09.162
日期:2008.12
An efficient and convenient method for the synthesis of 2-aryl substituted tetrahydropyran, tetrahydrofuran, and oxepine derivatives via intramolecular palladium catalyzed cyclization is developed. The two exo-cyclic double bonds at adjacent carbon atoms in these ring systems could serve as potential dienes for cycloadditionreactions.
Preparation of Allyltin Reagents Grafted on Solid Support: Clean and Easily Recyclable Reagents for Allylation of Aldehydes
作者:Jean-Mathieu Chrétien、Françoise Zammattio、Delphine Gauthier、Erwan Le Grognec、Michaël Paris、Jean-Paul Quintard
DOI:10.1002/chem.200501595
日期:2006.9.6
The preparation of polymer-supported allyltin reagents was shown to be possible for both unfunctionalized and functionalized allyl units. These reagents were treated with aldehydes in the presence of cerium(III) or indium(III) salts to afford high yields of homoallylic alcohols, practically uncontaminated with organotin residues (less than 5 ppm). Some mechanism aspects are briefly discussed and the
The Catalyzed Desulfinylative Allylation of Carbonyl Compounds with Alk-2-enesulfonyl Chlorides and Silyl Alk-2-enesulfinates
作者:Chandra M. R. Volla、Dean Marković、Sylvain Laclef、Pierre Vogel
DOI:10.1002/chem.201000705
日期:——
Coupling up with sulfonyl chlorides: An ene reaction of alkenes with SO2⋅BCl3 permits the one‐pot conversion of simple alkenes into β,γ‐unsaturated sulfonyl chlorides or sulfinic silyl esters. These compounds can then be used as nucleophilic allylating agents with aldehydes and ketones to generate the corresponding homoallylic alcohols (see scheme) with good chemo‐ and diastereoselectivity in the presence