Catalytic Enantioselective Allenylation Reactions of Aldehydes with Tethered Bis(8-quinolinolato) (TBOx) Chromium Complex
作者:Guoyao Xia、Hisashi Yamamoto
DOI:10.1021/ja0679578
日期:2007.1.1
The utility of the new class of chiral ligand, tethered bis(8-quinolinol) (TBOxH), is further explored. Its chromiumcomplex, TBOxCr(III)Cl, effectively catalyzes the asymmetric allenylation reactions of various aldehydes at room temperature with high yields (up to 91%) and high enantioselectivities (up to 97% ee). The scope of the present method is shown to be wide, and this method represents an efficient
substrates 1 and 2 can be regioselectively converted into chiral allenyl alcohols 3 through the title reaction [Eq. (1)] with the synergetic reagent iPrSBEt2 and a chiral TiIV catalyst. The dramatic regioselectivity originates from the regulation of the equilibriumbetween propargyl- and allenylstannanes during the catalytic process.
Chiral Brønsted acid catalyzed enantioselective allenylation of aldehydes
作者:Leleti Rajender Reddy
DOI:10.1039/c2cc34371a
日期:——
A versatile and highly enantioselective chiral Brønsted acid-catalyzed allenylation of aldehydes with propargyl borolane is reported. The reaction is shown to be practical and quite general with a broad substrate scope covering aryl, heteroaryl, α,β-unsaturated, and aliphatic aldehydes.
Stereoselective construction of skipped polyol enabled by oxonia-Cope rearrangement and iodolactonization: enantioselective synthesis of (+)-yashabushitriol
作者:Guoli He、Yan Wang、Calvine Lai、Wenhua Li、Ran Hong
DOI:10.1007/s11426-016-0073-3
日期:2016.9
we devised a highly diastereoselective approach to access skipped triol (anti, syn-isomer) from a chiral α-allenicalcohol which was derived from kinetic resolution in our previous studies. An iodolactonization and subsequent radical deiodonation efficiently introduced the hydroxyl group at C3 in a highly diastereoselective manner and exemplified in enantioselective total synthesis of (+)-yashabushitriol