TY - JOUR
T1 - Generation of nucleophilic chromium acetylides from gem-trichloroalkanes and chromium Chloride
T2 - Synthesis of propargyl alcohols
AU - Dhurke, Kashinath
AU - Steve, Tisserand
AU - Narender, Puli
AU - Falck, J R
AU - Rachid, Baati
PY - 2010/4
Y1 - 2010/4
N2 - Nucleophilic mixed chromium(II) and chromium(III) acetylides are generated from the smooth reduction of primary 1,1,1-trichloroalkanes with chromium(II) chloride in the presence of an excess amount of triethylamine at room temperature. These species arise from chrornium(III) vinylidene carbenoids. It has been demonstrated that uncommon low-valent CrII acetylides are formed by C-H insertion of CrIICl2 into terminal alkynes, formed in situ through the FritschButtenberg-Wiechell (FBW) rearrangement, whereas CrIII acetylides are concomitantly generated by HCl elimination from the chromium(III) vinylidene carbenoid, Both divergent pathways result, overall, in the formation of nucleophilic acetylides. In situ trapping with electrophilic aldehydes afforded propargyl alcohols. Furthermore, deuteration experiments and the use of deuterium labeled 1,1,1-trichloroalkane substrates demonstrated the prevalence of low-valent Cr11 acetylides, potentially useful, yet highly elusive synthetic intermediates.
AB - Nucleophilic mixed chromium(II) and chromium(III) acetylides are generated from the smooth reduction of primary 1,1,1-trichloroalkanes with chromium(II) chloride in the presence of an excess amount of triethylamine at room temperature. These species arise from chrornium(III) vinylidene carbenoids. It has been demonstrated that uncommon low-valent CrII acetylides are formed by C-H insertion of CrIICl2 into terminal alkynes, formed in situ through the FritschButtenberg-Wiechell (FBW) rearrangement, whereas CrIII acetylides are concomitantly generated by HCl elimination from the chromium(III) vinylidene carbenoid, Both divergent pathways result, overall, in the formation of nucleophilic acetylides. In situ trapping with electrophilic aldehydes afforded propargyl alcohols. Furthermore, deuteration experiments and the use of deuterium labeled 1,1,1-trichloroalkane substrates demonstrated the prevalence of low-valent Cr11 acetylides, potentially useful, yet highly elusive synthetic intermediates.
KW - Alcohols
KW - Alkynes
KW - Carbenoids
KW - Chromium
KW - Rearrangement
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U2 - 10.1002/ejoc.200901476
DO - 10.1002/ejoc.200901476
M3 - Article
C2 - 21562621
AN - SCOPUS:77949863736
SN - 1434-193X
SP - 1869
EP - 1874
JO - European Journal of Organic Chemistry
JF - European Journal of Organic Chemistry
IS - 10
ER -