The asymmetric synthesis of γ-alkenyl butenolides was accomplished by conjugatedaddition of butenolides to alkynones. Both terminal alkynones and nonterminal alkynones were applicable to the N,N′-dioxide–scandium(III) catalytic system. The corresponding products were obtained in good to excellent yields (up to 99%) with high E/Z ratios and high enantioselectivities (up to 98% ee). The novel methods
An N,N′‐dioxide/zinc bis(trifluoromethylsulfonyl)imide complex has been developed as an efficient catalyst for the highly enantioselective Diels–Alderreaction of cyclopentadiene with alkynones. Various 2‐acyl substituted norbornadiene derivatives were obtained in moderate to high yields (up to 99 %) with good enantiomeric excesses (up to 95 %).
TfOH-promoted synthesis of indoles and benzofurans involving cyclative transposition of vinyl ketone
作者:Mou Mandal、Rengarajan Balamurugan
DOI:10.1039/d2cc03730k
日期:——
derived from o-alkynylanilines involving a cyclization, retro-aza-Michael reaction and amine trapping cascade is reported here. This atom-economical transformation has been extended to synthesize benzofuran derivatives using analogous vinylogous esters derived from o-alkynylphenols. The excellent stereochemical outcome of the double bond geometry in the products makes it attractive.
Wender, Paul A.; Stemmler, Rene T.; Sirois, Lauren E., Journal of the American Chemical Society, 2010, vol. 132, p. 2532 - 2533
作者:Wender, Paul A.、Stemmler, Rene T.、Sirois, Lauren E.
DOI:——
日期:——
Progress toward the Total Synthesis of Saudin: Development of a Tandem Stille-Oxa-Electrocyclization Reaction
作者:Uttam K. Tambar、Taichi Kano、Brian M. Stoltz
DOI:10.1021/ol050705b
日期:2005.6.1
[GRAPHICS]A diastereoselective tandem Stille-oxa-electrocyclization reaction provides access to the core of the diterpenoid natural product saudin. Additionally, this new reaction sequence was extended to the convergent preparation of related polycyclic pyran systems.