Rh(I) catalyzes the reductive coupling reaction of a wide variety of aldehydes with conjugateddienes in the presence of a stoichiometric amount of triethylborane to provide homoallyl alcohols in a single operation.
Ruthenium-Catalyzed C−C Bond Forming Transfer Hydrogenation: Carbonyl Allylation from the Alcohol or Aldehyde Oxidation Level Employing Acyclic 1,3-Dienes as Surrogates to Preformed Allyl Metal Reagents
作者:Fumitoshi Shibahara、John F. Bower、Michael J. Krische
DOI:10.1021/ja801213x
日期:2008.5.1
Under the conditions of ruthenium-catalyzedtransferhydrogenation, commercially available acyclic 1,3-dienes, butadiene, isoprene, and 2,3-dimethylbutadiene, couple to benzylic alcohols 1a-6a to furnish products of carbonyl crotylation 1b-6b, carbonyl isoprenylation 1c-6c, and carbonyl reverse 2-methyl prenylation 1d-6d. Under related transferhydrogenation conditions employing isopropanol as terminal
A series of new protocols for regiodivergent and enantioselective coupling of 1,1-disubstituted allenes and aldehydes promoted by easily accessible Co complexes were developed. These processes represent the first example of transformations through enantioselective oxidative cyclization of allenes and aldehydes with diverse regioselectivities accurately controlled by chiral ligands.
开发了一系列用于 1,1-二取代丙二烯和醛的区域发散和对映选择性偶联的新方案,这些方案由易于获得的 Co 络合物促进。这些过程代表了通过手性配体精确控制的具有不同区域选择性的丙二烯和醛的对映选择性氧化环化转化的第一个例子。