Year: 2011
Type: article
Abstract: An expeditious synthetic approach to a chiral phenol, a key building block in the preparation of a series of drug candidates, is reported by Caille and co-workers at Amgen (J.Org.Chem.2011, 76, 5198À5206).The strategy includes a cost-effective and readily scalable route to 2,2-dimethylcyclopentanone from isobutyronitrile.The sterically hindered and enolizable 2,2-dimethylcyclopentanone was subsequently employed in a challenging Grignard addition mediated by LaCl 3 3 2LiCl.A novel preparation of the lanthanide reagent required for this transformation is also described.To complete the process, a highly enantioselective Rh-catalyzed hydrogenation afforded the target chiral phenol.The importance of the phenol group to the success of this asymmetric transformation is discussed. ' PHENYLGLYCINE-DERIVED CHIRAL SULFINYL TRANSFER AGENTChiral sulfinyl-containing reagents, such as sulfoxides and sulfinamides, have been recognized as useful tools in the asymmetric synthesis of complex organic molecules.Although the power of chiral sulfinyl reagents in synthetic chemistry has long been recognized, methods for their synthesis have emerged slowly.Now Han and co-workers at Boehringer Ingelheim report on a new chiral sulfinyl transfer auxiliary derived from readily available phenylglycine (J.Org.Chem.2011, 76, 5480À5484).This auxiliary can be utilized to synthesize a diverse array of alkyland arylsulfinamides and sulfinylferrocenes in high yields and excellent ee's.The desired products are produced in a one-pot sequence from the oxathiazolidine 2-oxide by two sequential nucleophilic additions that proceed in a stereospecific manner. ' Cu-MEDIATED BENZIMIDAZOLE AND BENZOXA-ZOLE SYNTHESISBenzimidazoles and benzoxazoles are privileged structural units that are encountered in a wide range of biologically active and medicinally significant compounds.An efficient method for the transformation of N-benzyl bisarylhydrazones and bisaryloxime Downloaded via 24.63.3.
DOI: 10.1021/op200215n
Authors: Mark McLaughlin, Ian Wilson, Wenyi Zhao, Andrei Zlota, Trevor Laird
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4246894045