Subject(s)
Arabidopsis Proteins , Arabidopsis , Seedlings , Seeds , Transcription Factors , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis/growth & development , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/genetics , Seeds/growth & development , Seeds/metabolism , Seeds/genetics , Transcription Factors/metabolism , Transcription Factors/genetics , Seedlings/genetics , Seedlings/growth & development , Seedlings/metabolism , Gene Expression Regulation, Plant , Repressor Proteins/metabolism , Repressor Proteins/geneticsABSTRACT
A Pd-catalyzed reductive addition of organohalides, including aryl, alkenyl, and benzyl halides, to ynol ethers has been realized in the presence of 2-propanol, giving α,ß- and ß,ß-disubstituted olefinic ethers in satisfactory yields with excellent regio- and stereoselectivity. It represents the first highly regio- and stereoselective hydroarylation, hydroalkenylation, and hydrobenzylation of ynol ethers.
ABSTRACT
An operationally simple and practical protocol for the synthesis of (E)-α-halo vinyl sulfides has been achieved via a highly regio- and stereoselective hydrohalogenation of alkynyl thioethers using lithium halides in HOAc or propionic acid at room temperature. It permits the formation of (E)-α-chloro and (E)-α-bromo vinyl sulfides in satisfactory yields with good to excellent stereoselectivities. Moreover, this work results in a new method for the assembly of stereodefined (E)- or (Z)-trisubstituted alkenes featuring the first coupling of the C-X bond of (E)-α-halo vinyl sulfides followed by a subsequent Ni-catalyzed coupling of the C-S bond with Grignard reagents.
Subject(s)
Alkenes/chemical synthesis , Alkynes/chemistry , Hydrocarbons, Halogenated/chemical synthesis , Sulfhydryl Compounds/chemistry , Sulfides/chemical synthesis , Alkenes/chemistry , Hydrocarbons, Halogenated/chemistry , Molecular Structure , Stereoisomerism , Sulfides/chemistryABSTRACT
An unprecedented Pd-catalyzed hydrohalogenation of alkynyl halides for the regio- and stereoselective synthesis of (Z)-1,2-dihaloalkenes has been realized using [(allyl)PdCl](2) as the catalyst and cis,cis-1,5-cyclooctadiene as the ligand. The advantages of this protocol are well illustrated by the assembly of trisubstituted (Z)-enynes and multifunctional benzenes via iterative cross-coupling reactions or tandem Diels-Alder-aromatization reactions, respectively.
ABSTRACT
A highly regio- and stereoselective method for the synthesis of cis-1,2-dihaloalkenes through Pd-catalyzed coupling of haloalkynes and α,ß-unsaturated carbonyls has been reported. Excellent stereoselectivities (Z/E up to >98:2) were observed in most cases. This method was subsequently applied to synthesize the functionalized conjugated enyne via the mono-Sonogashira coupling reaction of cis-1-chloro-2-iodoalkene.