An alkyne hydrosilylation-oxidation strategy for the selective installation of oxygen functionality.
Alkynes bearing propargylic, homopropargylic, and bishomopropargylic hydroxyl groups are shown to serve as precursors for ketone or alpha-hydroxy ketone functionality. The approach hinges on the intermediacy of vinylsilanes created through regioselective hydrosilylation catalyzed by the complex [Cp*Ru(MeCN)3]PF6. Several oxidative pathways of linear and cyclic vinylsilanes are studied, and the possibility of diastereoselective epoxidation of cyclic vinylsilanes is demonstrated. The sequences constitute the equivalent of stereoselective aldol, homo-aldol, and bishomo-aldol type processes. The method is applied to a short synthesis of the piperidine alkaloid, spectaline.
Trost
Barry M
BM
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA. bmtrost@stanford.edu
Ball
Zachary T
ZT
Laemmerhold
Kai M
KM
D000447:Aldehydes / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry*; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry* / Q000502:physiology; D010880:Piperidines / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
D000447:Aldehydes; D000480:Alkynes; D017646:Organosilicon Compounds; D010880:Piperidines; C480880:spectaline; C116609:3-hydroxybutanal; D010100:Oxygen