title: Synthesis of 6- and 7-Membered N-Heterocycles Using α-Phenylvinylsulfonium Salts.
abstract: A concise synthesis of stereodefined C-substituted morpholines, piperazines, azepines, and oxazepines in moderate to excellent yields (27% to 75%) is reported by reaction of 1,2- or 1,3-amino alcohol/1,2- or 1,3-diamine with an α-phenylvinylsulfonium salt. High levels of regio- and diastereoselectivity (from 2:1 to >20:1) are observed through judicious choice of base (Cs2CO3) and solvent (CH2Cl2). Reactions are performed at ambient temperature and open to air and do not require anhydrous solvent. The deprotection of the N-sulfonamide protecting groups (N-Ts and N-Ns) is also demonstrated. Factors affecting regio- and diastereocontrol are discussed.
authors.affiliation: School of Chemistry, University of Bristol , Cantock's Close, BS8 1TS, Bristol, U.K.
authors.forename: Johnathan V
authors.initials: JV
authors.lastname: Matlock
authors.affiliation: School of Chemistry, University of Bristol , Cantock's Close, BS8 1TS, Bristol, U.K.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Svejstrup
authors.affiliation: School of Chemistry, University of Bristol , Cantock's Close, BS8 1TS, Bristol, U.K.
authors.forename: Pradip
authors.initials: P
authors.lastname: Songara
authors.affiliation: School of Chemistry, University of Bristol , Cantock's Close, BS8 1TS, Bristol, U.K.
authors.forename: Sarah
authors.initials: S
authors.lastname: Overington
authors.affiliation: Centre for Synthesis and Chemical Biology, UCD School of Chemistry, University College Dublin , Belfield, Dublin 4, Ireland.
authors.forename: Eoghan M
authors.initials: EM
authors.lastname: McGarrigle
authors.affiliation: School of Chemistry, University of Bristol , Cantock's Close, BS8 1TS, Bristol, U.K.
authors.forename: Varinder K
authors.initials: VK
authors.lastname: Aggarwal
mesh_terms: D000605:Amino Alcohols / Q000737:chemistry*; D001381:Azepines / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003959:Diamines / Q000737:chemistry*; D015394:Molecular Structure; D009025:Morpholines / Q000138:chemical synthesis* / Q000737:chemistry; D010077:Oxazepines / Q000138:chemical synthesis* / Q000737:chemistry; D010879:Piperazines / Q000138:chemical synthesis; D013237:Stereoisomerism; D013452:Sulfonium Compounds / Q000737:chemistry*
chemical_list: D000605:Amino Alcohols; D001381:Azepines; D003959:Diamines; D009025:Morpholines; D010077:Oxazepines; D010879:Piperazines; D013452:Sulfonium Compounds