<sup>187</sup>Os NMR Study of (η<sup>6</sup>-Arene)osmium(II) Complexes: Separation of Electronic and Steric Ligand Effects
作者:Andrew G. Bell、Wiktor Koźmiński、Anthony Linden、Wolfgang von Philipsborn
DOI:10.1021/om960053i
日期:1996.7.9
acceptor character of the phosphorus ligand, and a relationship between Os−P bondlengths and coupling constants was found. Osmium relaxation rates T1-1 and their B0 field dependence are reported for selected complexes. The crystalstructures of four Os(p-cymene)Cl2L complexes (L = PMe3 (1), P(OMe)3 (6), PBz3 (13), and PPh3 (15)) have been determined.
Isotope effects and the distinction between synchronous, asynchronous, and stepwise Diels–Alder reactions
作者:Daniel A. Singleton、Brian E. Schulmeier、Chao Hang、Allen A. Thomas、Shun-Wang Leung、Steven R. Merrigan
DOI:10.1016/s0040-4020(01)00354-4
日期:2001.6
variety of symmetrical or nearly symmetrical Diels–Alder reactions are studied by a combination of experimental isotope effects, theoretical calculations, and rate observations. Becke3LYP calculations predicted highly asynchronous transition structures for Diels–Alder reactions of bis(boryl)acetylenes, dialkyl acetylenedicarboxylates, triazolinediones, and dialkyl maleates. Rate observations and kinetic
2-Trimethylsilylvinylboranes: highly reactive and selective diels-alder equivalents of 2-trimethylsilylvinyl alcohol and acetylene
作者:Daniel A Singleton、Jose P Martinez
DOI:10.1016/0040-4039(91)80108-i
日期:1991.12
The readily available 2-trimethylsilylvinyl-9-BBN (1) is a highlyreactive and selective dienophile. The Diels-Alder products are easily converted into trimethylsilylcyclohexenols and 1,4-cyclohexadienes.