21960-27-0Relevant articles and documents
Synthetic and Spectroscopic Investigations Enabled by Modular Synthesis of Molecular Phosphaalkyne Precursors
Transue, Wesley J.,Yang, Junyu,Nava, Matthew,Sergeyev, Ivan V.,Barnum, Timothy J.,McCarthy, Michael C.,Cummins, Christopher C.
supporting information, p. 17985 - 17991 (2019/01/09)
A series of dibenzo-7-phosphanorbornadiene compounds, Ph3PC(R)PA (1-R; A = C14H10, anthracene; R = Me, Et, iPr, sBu), are reported to be capable of thermal fragmentation to generate alkyl-substituted phosphaalkynes (RC≡P) concomitant with triphenylphosphine and anthracene. Facile preparation of these molecular precursors proceeds by treatment of ClPA with the appropriate ylide Ph3P=CHR (2 equiv). For methyl, ethyl, and isopropyl substituents, the phosphaalkyne conversions are measured to be 56-73% in solution by quantitative 31P NMR spectroscopy. In the case of compound 1-Me, the kinetic profile of its spontaneous unimolecular fragmentation is investigated by an Eyring analysis. The resulting 1-phosphapropyne is directly detected by solution NMR spectroscopy and gas phase rotational microwave spectroscopy. The latter technique allows for the first time measurement of the phosphorus-31 nuclear spin-rotation coupling tensor. The nuclear spin-rotation coupling provides a link between rotational and NMR spectroscopies, and is contextualized in relation to the chemical shift anisotropy.
Gold catalysis: Synthesis of 3-acylindenes from 2-alkynylaryl epoxides
Hashmi, A. Stephen K.,Buehrle, Miriam,Salathe, Ralph,Bats, Jan W.
supporting information; experimental part, p. 2059 - 2064 (2009/08/07)
A series of 2-alkynylaryl epoxides were prepared by a sequence of Sonogashira coupling, Wittig olefination and epoxidation or a Darzens' glycid ester synthesis. The conversion of these substrates with gold(I) catalysts furnished 3-acylindenes and, in occa
Cyclocondensation of oxalyl chloride with 1,2-glycols
Iida,Itaya
, p. 10511 - 10530 (2007/10/02)
Oxalyl chloride reacts with a wide range of acyclic 1,2-glycols 1 in the presence of triethylamine to produce 1,3-dioxolan-2-ones 3 together with 1,4-dioxane-2,3-diones 2. Ethylene glycol (1d), monosubstituted ethylene glycols 1e, j-l, and erythro-1,2-disubstituted ethylene glycols 1f, m, o provide the cyclic carbonates 3 as the minor products, while the threo-compounds 1g, i, n, p, q and pinacol (1h) afford 3 as the main products. The formation of 3 may be rationalized in terms of stereoelectronically controlled cleavage of the conjugate base 17- of the tetrahedral intermediates. The rate of the conformational change of 17- into 18- and the equilibrium constant between these conformers are proposed to be the major factors affecting the reaction pattern.
