Chiral phosphinamides: new catalysts for the asymmetric reduction of ketones by borane
作者:Barry Burns、N. Paul King、Heather Tye、John R. Studley、Mark Gamble、Martin Wills
DOI:10.1039/a709174e
日期:——
We have identified a new class of catalysts for the asymmetricreduction of prochiral ketones by borane. Key to the architecture of effective catalysts is an N–PO structural unit which may be part of a phosphinamide, phosphonamide or a related structure. Such catalysts are simple to prepare, are often crystalline solids and may be recovered from reduction reactions and reused. The catalysts act essentially
Catechol-Based Phosphoramidites: A New Class of Chiral Ligands for Rhodium-Catalyzed Asymmetric Hydrogenations
作者:Rob Hoen、Michel van den Berg、Heiko Bernsmann、Adriaan J. Minnaard、Johannes G. de Vries、Ben L. Feringa
DOI:10.1021/ol049726g
日期:2004.4.1
[reaction: see text] The synthesis and application of a new class of catechol-based phosphoramidites is described. Ees up to 99% were obtained in the rhodium-catalyzedasymmetrichydrogenation of dehydroamino acids and enamides.
作者:Raphael S. Kim、Linh V. Dinh-Nguyen、Kirk W. Shimkin、Donald A. Watson
DOI:10.1021/acs.orglett.0c03061
日期:2020.10.16
copper catalyst system, an efficient α-functionalization of nitroalkanes with propargyl bromides is now established. This mild and robust method is highly functional group tolerant and provides straightforward access to complex secondary and tertiary homopropargylic nitroalkanes. Moreover, the utility of these α-propargylated nitroalkanes is demonstrated through downstream functionalization to biologically
Design, Development, and Scale-Up of a Selective <i>meso</i>-Epoxide Desymmetrization Process
作者:David L. Varie、Christopher Beck、Sandra K. Borders、Molly D. Brady、Jason S. Cronin、Tracy K. Ditsworth、David A. Hay、David W. Hoard、Richard C. Hoying、Ryan J. Linder、Richard D. Miller、Eric D. Moher、Jacob R. Remacle、John A. Rieck、David D. Anderson、Paul N. Dodson、Mindy B. Forst、Duane A. Pierson、Joseph A. Turpin
DOI:10.1021/op060225f
日期:2007.5.1
converted to ketone 2b, a key intermediate in a new asymmetric synthesis of LY459477. Chiral diamine 17 was prepared from a readily available chiral precursor, (R)-α-methylbenzylamine, and could be recovered from the reaction mixture and reused. Studies performed to probe the mechanism of the rearrangement reaction of epoxide 4b showed that diamine 17 provided an optimal combination of selectivity and scaleability
An enantioselective C–H functionalization route to perfluoroalkyl-containing 3-azabicyclo[3.1.0]hexanes is disclosed. A modular and bench-stable diazaphospholane ligand enables highly enantioselective Pd(0)-catalyzed cyclopropane C–H functionalization using trifluoroacetimidoyl chlorides as electrophilic partners. In turn, the resulting cyclic ketimine products react smoothly with a broad variety of