Heterogeneous Parahydrogen Pairwise Addition to Cyclopropane

Highly enantioselective addition of phenylethynylzinc to aldehydes catalyzed by chiral cyclopropane-based amino alcohols.

The enantioselective addition of phenylethynylzinc to aldehydes catalyzed by a series of cyclopropane-based amino alcohol ligands 7 was investigated. The reactions afforded chiral propargylic alcohols in high yields (up to 96%) and with excellent enantioselectivities (up to 98% ee) under mild conditions. Furthermore, studies on the structural relationship show that the matching of the chiral ce...

Parahydrogen-induced polarization by pairwise replacement catalysis on Pt and Ir nanoparticles.

Pairwise and random addition processes are ordinarily indistinguishable in hydrogenation reactions. The distinction becomes important only when the fate of spin correlation matters, such as in parahydrogen-induced polarization (PHIP). Supported metal catalysts were not expected to yield PHIP signals given the rapid diffusion of H atoms on the catalyst surface and in view of the sequential stepw...

Transfer of Parahydrogen-Induced Polarization to 19F:

Introduction Parahydrogen-Induced Polarization (PHIP) leads to strong signal enhancement in H-NMR if unsaturated substrates are hydrogenated with parahydrogen (p-H2) applying an appropriate catalyst. As shown before, this polarization can be transferred to heteronuclei such as C. For imaging the lung, a F-hyperpolarized contrast agent should be available, if possible for inhalation. Normally, t...

Cyclopropane Anæsthesia

TLHIS paper is based on my experience of one thousand cases of cyclopropane anaesthesia personally conducted by me since October, 1938, both in hospital and in private. But before discussing these it might be convenient for me to mention here something about the drug itself. HISTORY. Cyclopropane was first isolated in Germany in 1882 by Freund, who also demonstrated its chemical structure, C 3H...

Cyclopropane Anesthesia