Copper-Catalyzed Syntheses of Multiple Functionalizatized Allenes via Three-Component Reaction of Enynes
作者:Yulong Song、Chunling Fu、Shengming Ma
DOI:10.1021/acscatal.1c02140
日期:2021.8.6
oxime esters and 1,3-enynes in the presence of TMSCN or TMSCF3 has been developed. This mild protocol enjoys a broad substrate scope tolerating many functional groups, providing a facile access to 1,7-double-functionalized allenes, which are difficult to prepare. The allenyl nitrile products may be easily transformed into allenoic acid derivatives and stereodefined tetrasubstituted alkenes, demonstrating
Rhodococcus butanica ATCC 21197 preferentially hydrolyzed pro-S cyano group of 3-substituted glutaronitriles with an aromatic ring. A product with high e.e. (>99%) was obtained from 3-benzoyloxy derivative.
作者:John A. Crosby、Julian S. Parratt、Nicholas J. Turner
DOI:10.1016/s0957-4166(00)86057-7
日期:1992.12
A series of prochiral 3-hydroxyglutaronitrile derivatives 1–5 has been enzymically hydrolysed to the corresponding nitrile-carboxylic acids 1b–5b with enantiomeric excesses ranging from 22–84%. In all cases the products were of the (S)-configuration.
Stereoselective hydrolysis of nitriles and amides under mild conditions using a whole cell catalyst
作者:Timothy Beard、Mark A. Cohen、Julian S. Parratt、Nicholas J. Turner、John Crosby、Jock Moilliet
DOI:10.1016/s0957-4166(00)80215-3
日期:1993.6
An immobilised whole cell Rhodococcus sp. (SP 361) has been shown to be an effective catalyst for the stereoselective hydrolysis of both racemic and prochiral nitrile containing compounds. 2-Alkyl-arylacetonitriles 6a-8a were hydrolysed to (S)-acids and (R)-amides whereas the closely related substrate 9a gave the (R)-acid. A series of prochiral dinitriles 10a-13a were hydrolysed to the corresponding (S)-acids with e.e.'s 22-84%. Models to account for the stereoselectivity of the enzymic hydrolyses have been proposed.
A Stereodivergent Approach to Substituted 4-Hydroxypiperidines
作者:Mandy K. S. Vink、Christien A. Schortinghuis、Jordy Luten、Jan H. van Maarseveen、Hans E. Schoemaker、Henk Hiemstra、Floris P. J. T. Rutjes
DOI:10.1021/jo025943o
日期:2002.11.1
A stereodivergent route toward both diastereomeric forms of functionalized 4-hydroxypiperidines has been successfully developed. This route involves biocatalytic generation of the enantiopure starting materials followed by functionalization via N-acyliminium ion-mediated CC-bond formation.