Cyclization/Hydrosilylation of Functionalized 1,6-Diynes Catalyzed by Cationic Platinum Complexes Containing Bidentate Nitrogen Ligands

• Published in: Journal of organic chemistry Vol. 67; no. 9; pp. 2778 - 2788
• Main Authors: Wang, Xiang, Chakrapani, Harinath, Madine, James W, Keyerleber, Michele A, Widenhoefer, Ross A
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 03.05.2002; Amer Chemical Soc
• Subjects: Alkynes - chemistry; Catalysis; Chemistry; Chemistry, Organic; Cyclization; Drug Design; Exact sciences and technology; Hydrocarbons, Cyclic - chemical synthesis; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Structure; Nitrogen - chemistry; Organic chemistry; Organometalloidal and organometallic compounds; Organoplatinum Compounds - chemistry; Oxidation-Reduction; Physical Sciences; Preparations and properties; Science & Technology; Si derivatives; Silanes - chemistry; Stereoisomerism; ALPHA-OLEFINS; BIS-DIENES; 1,6-DIENES; PYRIDINE-OXAZOLINE COMPLEXES; PALLADIUM COMPLEX; PHENANTHROLINE COMPLEX; C-H ACTIVATION; MEDIATED TETRAENE CARBOCYCLIZATIONS; ENYNE COMPOUND; CYCLIZATION; Catalytic reaction; Transition element complexes; Sulfone; Platinum Organic compounds; Amides; Organic silane; Hydrosilylation; Dienic compound; Ketone; Platinum I Complexes; Acetal; Ester; Bidentate ligand; Cycloaddition; Cyclization; Platinoid Complexes; Transition metal Organic compounds; Diynic compound; Chemical synthesis; Cyclopentane derivatives
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo015986p

A 1:1 mixture of the platinum dimethyl diimine complex [PhNC(Me)C(Me)NPh]PtMe2 (4a) and B(C6F5)3 catalyzed the cyclization/hydrosilylation of dimethyl dipropargylmalonate (1) and HSiEt3 to form 1,1-dicarbomethoxy-3-methylene-4-(triethylsilylmethylene)cyclopentane (3) in 82% isolated yield with 26:1 Z:E selectivity. Platinum-catalyzed diyne cyclization/hydrosilylation tolerated a range of functional groups including esters, sulfones, acetals, silyl ethers, amides, and hindered ketones. Diynes that possessed propargylic substitution underwent facile cyclization/hydrosilylation to form silylated 1,2-dialkylidene cyclopentanes as mixtures of regioisomers. Diynes that possessed an electron-deficient internal alkyne underwent cyclization/hydrosilylation in moderate yield to form products resulting from silyl transfer to the less substituted alkyne. The silylated 1,2-dialkylidenecyclopentanes formed via diyne cyclization/hydrosilylation underwent a range of transformations including protodesilylation, Z/E isomerization, and [4 + 2] cycloaddition with dieneophiles.