Gold-Catalyzed Cyclizations of (o-Alkynyl)phenoxyacrylates with External Nucleophiles: Regio- and Stereoselective Synthesis of Functionalized Benzo[b]oxepines
摘要:
A catalytic approach to benzo[b]oxepines with high stereoselectivity by Au-catalyzed cyclization of (o-alkynyl)phenoxyacrylates with various nucleophiles under mild reaction conditions has been developed. Notably, the use of vinyl ether instead of alcohol could afford the same benzoxepines. The reaction may proceed by Au-catalyzed oligomerization of vinyl ether to release the alcohol, which then reacts with (o-alkynyl)phenoxyacrylates to furnish the benzoxepines.
We have developed highly enantioselective synthesis of functionalized helically chiral molecules via a Rh-catalyzed [2 + 2 + 2] cycloaddition and synthesis of ladder-type molecules via an unprecedented Rh-catalyzed formal [2 + 1 + 2 + 1] cycloaddition involving C−C triple bond cleavage.
An enantioselective intramolecular cyclization reaction of alkynyl esters was developed, which employs a Bronsted base catalyst generated in situ from a chiral Schiff base and t-BuOK. This reaction is a...
Organocatalytic Enantioselective Construction of Axially Chiral Sulfone-Containing Styrenes
作者:Shiqi Jia、Zhili Chen、Nan Zhang、Yu Tan、Yidong Liu、Jun Deng、Hailong Yan
DOI:10.1021/jacs.8b03211
日期:2018.6.13
describe herein an organocatalytic enantioselective approach for the construction of axially chiral sulfone-containing styrenes. Various axially chiral sulfone-containing styrene compounds were prepared with excellent enantioselectivities (up to >99% ee) and almost complete E/ Z selectivities (>99% E/ Z). Furthermore, the axially chiral sulfone-containing styrenes could be easily converted into phosphonic
Catalytic asymmetric construction of C-4 alkenyl substituted pyrazolone derivatives bearing multiple stereoelements
作者:Wande Zhang、Shiqiang Wei、Wenyao Wang、Jingping Qu、Baomin Wang
DOI:10.1039/d1cc01123e
日期:——
An organocatalyticasymmetric process was reported for the sterically precise construction of C-4 alkenyl substituted pyrazolone derivatives bearing multiple stereoelements. A series of interesting products featuring the union of a centrally chiral pyrazolone moiety and an axially chiral styrene unit were obtained in high yield with excellent diastereoselectivity and enantioselectivity (up to 99% ee
Full circle: New cyclic tris(spiroborate)s were prepared as molecular recognition modules for nanometer‐sized cationic guests. These cyclophanes were simply prepared by treating corresponding bis(2,3‐dihydroxynaphthalene)s with an equimolar amount of boric acid. The molecular recognition ability of these cyclic spiroborates was estimated in solution and crystal phases by the use of [Ir(tpy2)]3+ as