TY - JOUR
T1 - Platinum and ruthenium chloride-catalyzed cycloisomerization of 1-alkyl-2-ethynylbenzenes
T2 - Interception of π-activated alkynes with a benzylic C-H bond
AU - Tobisu, Mamoru
AU - Nakai, Hiromi
AU - Chatani, Naoto
PY - 2009/8/7
Y1 - 2009/8/7
N2 - (Chemical Equation Presented) Air-stable and commercially available alkynophilicmetal salts, such as PtCl2, PtCl4, and [RuCl2(CO)3]2, catalyze the cycloisomerization of 1-alkyl-2-ethynylbenzenes to produce substituted indenes even at an ambient temperature. Electrophilically activated alkynes can be intercepted by simple benzylic C-Hbonds at primary, secondary, and tertiary carbon centers. Mechanistic studies, such as labeling studies and kinetic isotope and substituent effects, indicate that the cycloisomerization proceeds through the formation of a vinylidene intermediate and turnover-limiting 1,5-shift of benzylic hydrogen.
AB - (Chemical Equation Presented) Air-stable and commercially available alkynophilicmetal salts, such as PtCl2, PtCl4, and [RuCl2(CO)3]2, catalyze the cycloisomerization of 1-alkyl-2-ethynylbenzenes to produce substituted indenes even at an ambient temperature. Electrophilically activated alkynes can be intercepted by simple benzylic C-Hbonds at primary, secondary, and tertiary carbon centers. Mechanistic studies, such as labeling studies and kinetic isotope and substituent effects, indicate that the cycloisomerization proceeds through the formation of a vinylidene intermediate and turnover-limiting 1,5-shift of benzylic hydrogen.
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U2 - 10.1021/jo901045g
DO - 10.1021/jo901045g
M3 - Article
C2 - 19537727
AN - SCOPUS:68049099258
VL - 74
SP - 5471
EP - 5475
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
SN - 0022-3263
IS - 15
ER -