skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Borane-Catalyzed Selective Hydrosilylation of Internal Ynamides Leading to β-Silyl ( Z )-Enamides

; ; ORCiD logo
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Center for Catalytic Hydrocarbon Functionalization (CCHF)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Organic Letters; Journal Volume: 19; Journal Issue: 1; Related Information: CCHF partners with University of Virginia (lead); Brigham Young University; California Institute of Technology; Colorado School of Mines; University of Maryland; University of North Carolina, Chapel Hill; University of North Texas; Princeton University; The Scripps Research Institute; Yale University
Country of Publication:
United States

Citation Formats

Kim, Youngchan, Dateer, Ramesh B., and Chang, Sukbok. Borane-Catalyzed Selective Hydrosilylation of Internal Ynamides Leading to β-Silyl ( Z )-Enamides. United States: N. p., 2017. Web. doi:10.1021/acs.orglett.6b03485.
Kim, Youngchan, Dateer, Ramesh B., & Chang, Sukbok. Borane-Catalyzed Selective Hydrosilylation of Internal Ynamides Leading to β-Silyl ( Z )-Enamides. United States. doi:10.1021/acs.orglett.6b03485.
Kim, Youngchan, Dateer, Ramesh B., and Chang, Sukbok. Fri . "Borane-Catalyzed Selective Hydrosilylation of Internal Ynamides Leading to β-Silyl ( Z )-Enamides". United States. doi:10.1021/acs.orglett.6b03485.
title = {Borane-Catalyzed Selective Hydrosilylation of Internal Ynamides Leading to β-Silyl ( Z )-Enamides},
author = {Kim, Youngchan and Dateer, Ramesh B. and Chang, Sukbok},
abstractNote = {},
doi = {10.1021/acs.orglett.6b03485},
journal = {Organic Letters},
number = 1,
volume = 19,
place = {United States},
year = {Fri Jan 06 00:00:00 EST 2017},
month = {Fri Jan 06 00:00:00 EST 2017}
  • SiAlON ceramics, solid solutions based on the Si 3N 4 structure, are important, lightweight structural materials with intrinsically high strength, high hardness, and high thermal and chemical stability. Described by the chemical formula β-Si 6–zAl zO zN 8–z, from a compositional viewpoint, these materials can be regarded as solid solutions between Si 3N 4 and Al 3O 3N. A key aspect of the structural evolution with increasing Al and O (z in the formula) is to understand how these elements are distributed on the β-Si 3N 4 framework. The average and local structural evolution of highly phase-pure samples of β-Simore » 6–zAl zO zN 8–z with z = 0.050, 0.075, and 0.125 are studied here, using a combination of X-ray diffraction, NMR studies, and density functional theory calculations. Synchrotron X-ray diffraction establishes sample purity and indicates subtle changes in the average structure with increasing Al content in these compounds. Solid-state magic-angle-spinning 27Al NMR experiments, coupled with detailed ab initio calculations of NMR spectra of Al in different AlO qN 4–q tetrahedra (0 ≤ q ≤ 4), reveal a tendency of Al and O to cluster in these materials. Independently, the calculations suggest an energetic preference for Al–O bond formation, instead of a random distribution, in the β-SiAlON system.« less
  • Addition of the silane PPh[sub 2]CH[sub 2]CH[sub 2]SiMe[sub 2]H (chelH, 1a) to Pt(COD)[sub 2] (COD = cycloocta-1,5-diene) affords in high yield the cis-bis chelate Pt(chel)[sub 2] (2); formation of the same product from Pt(COD)(X)Y (X = Y = Me; X = Me, Y = Cl) has been shown by NMR spectroscopy ([sup 1]H, [sup 31]P, [sup 195]Pt) to proceed via prior coordination of chelH through P to afford Pt(chelH)[sub 2](X)(Y) (cis and trans isomers) and through intermediacy of PtH(chel)[sub 2]Cl (22) in which P trans to Si at Pt(IV) leads to an exceptionally low [sup 2]J(Pt-P) = 1084 Hz. Cleavagemore » of Pt-Si bonds in 2 by HCl can be controlled to give the monochelate species Pt(chel)(chelH)Cl (7), from which chelH is displaced by PMe[sub 2]Ph, or trans-PtH(PPh[sub 2]CH[sub 2]SiMe[sub 2]Cl)[sub 2]Cl (9). Products related to 9 result from Pt-Si bond cleavage by I[sub 2] or MeI. Using the analogue PPh[sub 2]CH[sub 2]CH[sub 2]SiMe(Ph)H (1c) of 1a, the analogue Pt-[PPh[sub 2]CH[sub 2]CH[sub 2]SiMe(Ph)][sub 2] (4) of 2 is obtained as a mixture of meso and racemic diastereomers in which the latter predominates, as is established by its separation and then reaction with optically pure (+)-2-methylbutyl iodide to give two diastereomeric products of Pt-Si bond cleavage as well as by single-crystal X-ray diffraction.« less
  • A recent experiment on DIII-D, which was conducted by the joint research team from DIII-D and EAST, has extended the previous high β p, high q min regime, which has been tested in the 2013 DIII-D/EAST joint experiment, to inductive operation at higher plasma current (I p=0.8 MA) and significantly higher normalized fusion performance (G = H 89β N/=qmore » $$2\atop{95}$$ = 0.16). The experiment aims at exploring high performance scenario with q min > 2 and reduced torque for long pulse operation, which can be potentially extrapolated to EAST. The effort was largely motivated by the interest in developing a feasible scenario for long-pulse high performance operation with low torque on EAST. Very high confinement, H 89 = 3.5 or H 98,y2 = 2.1 with β N ~ 3.0, has been achieved transiently in this experiment together with q min > 2 and reduced NBI torque (3~5 N-m). The excellent confinement is associated with the spontaneous formation of an internal transport barrier (ITB) in plasmas with I p=0.8 MA at large minor radius (normalized p ~ 0.7) in all channels (n e, T e, T i, V Φ, especially strong in the T e channel). Fluctuation measurements show a significant reduction in the fluctuation levels, including AE modes and broadband turbulence, at the location where an ITB forms. Linear gyrokinetic simulations also support the decrease of the growth rate of the most unstable mode during strong ITB formation. The simulation implies that strong suppression of turbulence and a positive feedback loop may be active in this process and is responsible for the spontaneous formation of large-radius ITB. Finally, in an unstable ITB phase, an ELM crash is observed to have a positive effect on transient formation of large-radius ITB. The formation of this kind of ITB is found to have a shielding (protecting) effect on the core plasma while isolating the perturbation due to ELM crash.« less