Supporting Information
Rhodium-Catalyzed Hydroformylation of Cyclopropenes William M. Sherrill and Michael Rubin* Department of Chemistry, The Univeristy of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045-75832
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Table of Contents: General Information........................................................................................................ 2 Special Equipment .......................................................................................................... 3 Construction of the Synthesis Gas Manifold .................................................................. 3 Preparation of Starting Materials .................................................................................... 5 Optimization Procedure .................................................................................................. 6 Preparative Procedures.................................................................................................... 7 Preparative Procedure for Asymmetric Hydroformylation........................................... 10 Assignment of Absolute Configuration ........................................................................ 12 Structures of Chiral Ligands Used in the Asymmetric Hydroformylation of Cyclopropenes............................................................................................................... 13 Complete Reference 11d:.............................................................................................. 16 Spectral Charts .............................................................................................................. 17
SI2
General Information NMR spectra were recorded on a Bruker Avance DPX-400 instrument, equipped with a quadruple-band gradient probe (H/C/P/F QNP) or Bruker Avance DRX-500 with a dual carbon/proton cryoprobe (CPDUL). 13C NMR spectra were registered with broadband decoupling. (+) and (-) represent positive and negative intensities of signals in 13C DEPT-135 experiments. Column chromatography was carried out employing silica gel (Selecto Scientific, 63-200 μm). Pre-coated silica gel plates (Merck Kieselgel 60 F-254) were used for thin-layer chromatography. GC/MS analyses were performed on a Shimadzu GC-2010 gas chromatograph interfaced to a Shimadzu GCMS 2010S mass selective detector, and equipped with an AOC-20i auto-injector and an AOC-20S autosampler tray (150 vials). 30 m x 0.25 mm x 0.25 μm capillary column, SHR5XLB, polydimethylsiloxane, 5% Ph was employed. Helium (99.96%), additionally purified by passing consecutively through a CRS oxygen/moisture/hydrocarbon trap (#202839) and VICI oxygen/moisture trap (P100-1), was used as a carrier gas. The same model of gas chromatograph, equipped with the same auto-injector, FID detector, and J&W CyclosilB column (30 m x 0.25 mm x 0.25 μm) was employed for chiral GC analyses. Hydrogen gas was used as both carrier gas and FID fuel; zero-grade air and zero-grade nitrogen were used as an oxidant and make-up gas, respectively, for the FID. All these gases were purified by passing through CRS #202839 traps. IR spectra were recorded on a Shimadzu FT-IR 8400S instrument. Optical rotations were measured on an Autopol IV polarimeter (Rudolph Research Analytical) using a 10 cm quartz cell. High resolution mass-spectra were obtained using a LCT Premier (Micromass Technologies) instrument using electrospray inonization and time of flight detection techniques. Anhydrous toluene, diethyl ether, and tetrahydrofuran were obtained by passing degassed HPLC-grade commercially available solvents consecutively through two columns with activated alumina (Innovative Technology). Anhydrous dimethylsulfoxide was purchased form Acros Organics and used as received. The Rh(CO)2(acac) complex was purchased from Sigma-Aldrich, and phosphine ligands were obtained from Strem Chemicals. Starting materials: 3-methyl-3-phenylcyclopropene (4a), 1,2 1-chloro-4-(1methylcycloprop-2-en-1-yl)benzene (4b), 2 1-fluoro-4-(1-methylcycloprop-2-en-1-yl)benzene (4c),2 [1-[(methoxymethoxy)methyl]-2-cyclopropen-1-yl]-benzene (4d), 3 (1phenylcycloprop-2-en-1-yl)methyl acetate (4e),3 methyl 1-phenylcycloprop-2-ene-1carboxylate (4f), 4 and 1-methylcycloprop-2-ene-1-carboxylate (4g)4,5 1,3-dimethyl-3phenylcyclopropene (4i), 6 1-methyl-4-(1-methylcycloprop-2-en-1-yl)benzene (4j)2 were prepared according to the published procedures. Preparative procedures for synthesis cyclopropene 4h are provided below. Syngas (equimolar mixture of hydrogen and (1) Rubin, M.; Gevorgyan, V. Synthesis 2004, 796. (2) Sherrill, M.; Kim, R.; Rubin, M. Tetrahedron 2008, 64, 8610. (3) Rubina, M.; Rubin, M.; Gevorgyan, V. J. Am. Chem. Soc. 2004, 126, 3688. (4) Rubina, M.; Rubin, M.; Gevorgyan, V. J. Am. Chem. Soc. 2003, 125, 7198. (5) Kudrevich, S. V.; Rubin, M. A.; Tarabaeva, O. G.; Surmina, L. S.; Berd, M. S.; Bolesov, I. G. Zh. Org. Khim. 1994, 30, 945. (6) Rubina, M.; Rubin, M.; Gevorgyan, V. J. Am. Chem. Soc. 2002, 124, 11566.
SI3 carbon monoxide, certified Standard Spec.) was purchased from Airgas and used as received. All other chemicals were purchased from Sigma-Aldrich or Acros Organics, and used as received. All manipulations with cyclopropenes and cyclopropylcarboxaldehydes were conducted under inert atmosphere (
