In situ formation of ligand and catalyst—application in ruthenium-catalyzed enantioselective reduction of ketones

2005 ◽  
pp. 4039 ◽  
Author(s):  
Patrik Västilä ◽  
Jenny Wettergren ◽  
Hans Adolfsson
Keyword(s):  
Enantioselective Reduction ◽  
In Situ Formation ◽  
Reduction Of Ketones

Practical Enantioselective Reduction of Ketones Using Oxazaborolidine Catalyst Generated in situ from Chiral Lactam Alcohols and Borane.

ChemInform ◽  
2004 ◽  
Vol 35 (5) ◽  
Author(s):  
Yasuhiro Kawanami ◽  
Shinichi Murao ◽  
Takahiko Ohga ◽  
Nobuyo Kobayashi
Keyword(s):  
Enantioselective Reduction ◽  
Reduction Of Ketones

Practical enantioselective reduction of ketones using oxazaborolidine catalyst generated in situ from chiral lactam alcohol and borane

Tetrahedron ◽  
2003 ◽  
Vol 59 (42) ◽  
pp. 8411-8414 ◽  
Author(s):  
Yasuhiro Kawanami ◽  
Shinichi Murao ◽  
Takahiko Ohga ◽  
Nobuyo Kobayashi
Keyword(s):  
Enantioselective Reduction ◽  
Reduction Of Ketones

scholarly journals Practical Enantioselective Reduction of Ketones Using Oxazaborolidine Catalysts Generated In Situ from Chiral Lactam Alcohols

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2408 ◽  
Author(s):  
Yasuhiro Kawanami ◽  
Ryo Yanagita
Keyword(s):  
Practical Method ◽  
Enantioselective Reduction ◽  
Trifluoromethyl Ketones ◽  
Aliphatic Ketones ◽  
Borane Reduction ◽  
Absolute Stereochemistry ◽  
Reduction Of Ketones

Oxazaborolidine catalyst (CBS catalyst) has been extensively used for catalytic borane reduction with a predictable absolute stereochemistry and high enantioselectivity. However, the use of isolated CBS catalyst sometimes has the drawback of low reproducibility due to the aging of the CBS catalyst during storage. Therefore, we investigated a more reliable and practical method for the reduction of a variety of ketones including challenging substrates, primary aliphatic ketones, α,β-enones, and trifluoromethyl ketones. This review surveys the developments in borane reduction using oxazaborolidine catalysts generated in situ from chiral lactam alcohols and borane.

scholarly journals Formation of compact systems of super-Earths via dynamical instabilities and giant impacts

2019 ◽  
Vol 491 (4) ◽  
pp. 5595-5620 ◽  
Author(s):  
Sanson T S Poon ◽  
Richard P Nelson ◽  
Seth A Jacobson ◽  
Alessandro Morbidelli
Keyword(s):  
Initial Conditions ◽  
Post Processing ◽  
Significant Modification ◽  
Kepler Mission ◽  
Giant Impacts ◽  
Low Mass ◽  
In Situ Formation ◽  
Dynamical Instabilities ◽  
Gaseous Envelopes

ABSTRACT The NASA’s Kepler mission discovered ∼700 planets in multiplanet systems containing three or more transiting bodies, many of which are super-Earths and mini-Neptunes in compact configurations. Using N-body simulations, we examine the in situ, final stage assembly of multiplanet systems via the collisional accretion of protoplanets. Our initial conditions are constructed using a subset of the Kepler five-planet systems as templates. Two different prescriptions for treating planetary collisions are adopted. The simulations address numerous questions: Do the results depend on the accretion prescription?; do the resulting systems resemble the Kepler systems, and do they reproduce the observed distribution of planetary multiplicities when synthetically observed?; do collisions lead to significant modification of protoplanet compositions, or to stripping of gaseous envelopes?; do the eccentricity distributions agree with those inferred for the Kepler planets? We find that the accretion prescription is unimportant in determining the outcomes. The final planetary systems look broadly similar to the Kepler templates adopted, but the observed distributions of planetary multiplicities or eccentricities are not reproduced, because scattering does not excite the systems sufficiently. In addition, we find that ∼1 per cent of our final systems contain a co-orbital planet pair in horseshoe or tadpole orbits. Post-processing the collision outcomes suggests that they would not significantly change the ice fractions of initially ice-rich protoplanets, but significant stripping of gaseous envelopes appears likely. Hence, it may be difficult to reconcile the observation that many low-mass Kepler planets have H/He envelopes with an in situ formation scenario that involves giant impacts after dispersal of the gas disc.

scholarly journals Method for determining the thermal conductivity of in situ formation rock using drilling cuttings

AIP Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 065015
Author(s):  
Fu Yi ◽  
Xupeng Qi ◽  
Xuexin Zheng ◽  
Huize Yu ◽  
Wenming Bai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
In Situ Formation
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