68703-33-3Relevant articles and documents
Quasi-Concerted Allylic Rearrangement in the Reaction of Allylic Chlorides with Methyltin Tris(methanethiolate)
Katz, Howard Edan,Starnes, William H.
, p. 2758 - 2761 (1984)
trans-6-Chloro-4-decene (4), 3-chloro-1-heptene (7), and trans-1-chloro-2-heptene (9) are converted quantitatively into allylic methyl sulfides upon treatment with a molar equivalent of methyltin tris(methanethiolate) at 70 deg C in benzene-dichloromethane.Unlike the reactions of sodium thiolates with straight chain allylic chlorides, these nucleophilic displacements are accompanied by very significant amounts of allylic rearrangement, with the yields of rearranged sulfide being 78percent and 100percent for 4 and 7, respectively.In the case of 9, the yield of rearranged product drops from 33percent to 25percent when the extent of conversion increases from 40percent to 100percent.However, all of the product sulfides are stable under the reaction conditions, and the reactions seem to occur without concomitant dehydrochlorination or isomerization of the starting chlorides.Other salient features of these reactions are their autoaccelerating rates, a chloride reactivity order like that observed for SN1 solvolysis, the production of internal double bonds that are exclusively trans, and the failure of methanethiol to react with 4 in a control experiment.An attractive reaction mechanism, not yet established conclusively, involves the discharge of unsymmetrical (allylic cation) MeSn(SMe)nCl-4-n ion pairs (n = 1-3) via MeS ligand transfer.The implications of this investigation for the thermal stabilization of poly(vinyl chloride) are considered briefly, and the 13C NMR chemical shifts of several allylic chlorides and methyl sulfides are used to derive parameters that can be employed for shift predictions.
Construction of enantioenriched cyclic compounds by asymmetric allylic alkylation and ring-closing metathesis
Giacomina, Francesca,Alexakis, Alexandre
supporting information, p. 6710 - 6721 (2013/11/06)
A new approach to highly enantioenriched cyclic compounds (up to 98a€‰% ee) has been developed by using ω-ethylenic allylic substrates in a one-pot asymmetric allylic alkylation and ring-closing metathesis sequence. The starting compounds are synthetic equivalents of cyclic allylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands. A new approach to highly enantioenriched cyclic compounds (up to 98a€‰% ee) has been developed by using ω-ethylenic allylic substrates in a one-pot asymmetric allylic alkylation and ring-closing metathesis sequence. The starting compounds are synthetic equivalents of cyclic allylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands. Copyright
Diastereoselective formation of tetrahydrofurans via pd-catalyzed asymmetric allylic alkylation: Synthesis of the C13-C29 subunit of amphidinolide N
Trost, Barry M.,Rey, Jullien
supporting information, p. 5632 - 5635 (2013/01/15)
An efficient synthesis of the C13-C29 fragment of amphidinolide N is described. The synthesis relies on a new strategy involving Pd-catalyzed asymmetric allylic alkylation to generate diastereoselectively the cis- or trans-THF unit simply by varying the enantiomer of the ligand. The C19 hydroxyl-bearing stereocenter was introduced using a chelation-controlled allylation which led exclusively to a single diastereoisomer.
Enzyme-triggered enantioconvergent transformation of haloalkyl epoxides
Mayer, Sandra F.,Steinreiber, Andreas,Orru, Romano V. A.,Faber, Kurt
, p. 4537 - 4542 (2007/10/03)
Biocatalytic hydrolysis of 2,3-disubstituted rac-cis- and rac-trans-haloalkyl epoxides 1a-8a using the epoxide hydrolase activity of whole bacterial cells furnished the corresponding vicinal diols 1b-8b as intermediates; these (spontaneously) underwent ring closure to yield cyclic products 1c-6c through an enzyme-triggered cascade reaction. In particular, cis-configured substrates (1a, 3a, 5a, 7a) were transformed in an enantioconvergent fashion, which resulted in the formation of single stereoisomeric products in 100% des and up to 92% ees from the racemates.
An efficient synthesis of (-)-pestalotin and its enantiomer using Sharpless asymmetric dihydroxylation
Wang, Zhi-Min,Shen, Ming
, p. 3393 - 3396 (2007/10/03)
With Sharpless asymmetric dihydroxylation as a key step, syntheses of (-)-pestalotin and its enantiomer have been accomplished in a four-step sequence in high stereoselectivity.
One-step conversion of protected alcohols into alkyl halides using dimethylphosgeniminium salt
Schlama,Gouverneur,Mioskowski
, p. 3517 - 3520 (2007/10/03)
Efficient conversion of tetrahydro-2-pyranyl (THP)protected alcohols into the corresponding halides using dichlorophosgeniminium chloride in the presence of tetraalkylammonium halide.
