Enantioselective iridium-catalyzed carbonyl allylation from the alcohol or aldehyde oxidation level using allyl acetate as an allyl metal surrogate.
Protocols for highly enantioselective carbonyl allylation from the alcohol or aldehyde oxidation level are described based upon transfer hydrogenative C-C coupling. Exposure of allyl acetate to benzylic alcohols 1a-i in the presence of an iridium catalyst derived from [IrCl(cod)]2 and (R)-BINAP delivers products of C-allylation 2a-i. Employing isopropanol as terminal reductant, exposure of allyl acetate to aryl aldehydes 3a-i in the presence of an iridium catalyst derived from [IrCl(cod)]2 and (-)-TMBTP delivers identical products of C-allylation 2a-i. In all cases examined, exception levels of enantioselectivity are observed. Thus, enantioselective carbonyl allylation is achieved from the alcohol or aldehyde oxidation level in the absence of any preformed allylmetal reagents. These studies define a departure from preformed organometallic reagents in carbonyl additions that transcend the boundaries of oxidation level.
Kim
In Su
IS
University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, Texas 78712, USA.
Ngai
Ming-Yu
MY
Krische
Michael J
MJ
D000085:Acetates / Q000737:chemistry; D000438:Alcohols / Q000138:chemical synthesis* / Q000737:chemistry*; D000447:Aldehydes / Q000737:chemistry*; D000498:Allyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D001592:Benzyl Alcohols / Q000737:chemistry; D002384:Catalysis; D007495:Iridium / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D000085:Acetates; D000438:Alcohols; D000447:Aldehydes; D000498:Allyl Compounds; D001592:Benzyl Alcohols; D009942:Organometallic Compounds; D007495:Iridium; C498551:allyl acetate