Microwave‐Assisted Rhodium‐Complex‐Catalyzed Cascade Decarbonylation and Asymmetric Pauson–Khand‐Type Cyclizations
作者:Hang Wai Lee、Lai Na Lee、Albert S. C. Chan、Fuk Yee Kwong
DOI:10.1002/ejoc.200800272
日期:2008.7
Microwave-assisted Rh–diphosphane-complex-catalyzed dual catalysis is reported. This cooperative process provides [2+2+1] cycloadducts by sequential decarbonylation of aldehyde or formate and carbonylation of enynes within a short period of time. Various O-, N-, and C-tethered enynes were transformed into the corresponding products in good yields. The first enantioselective version of this microwave-accelerated
Enantioselective iodolactonization of allenoic acids
作者:Kenichi Murai、Nozomi Shimizu、Hiromichi Fujioka
DOI:10.1039/c4cc05414h
日期:——
An enantioselectiveiodolactonization reaction of allenoic acids has been developed using a trisimidazoline catalyst and I2. Our mechanistic study suggests the involvement of a pi-allyl cation intermediate in this reaction system.
phosphoramidites is a paracyclophane scaffold in which two aryl rings are tethered by both a 1,8‐biphenylene unit and a O−P−O bridge. Suitable aryl substituents generate planar chirality. The corresponding gold(I) complexes promote the cycloisomerization of prochiral nitrogen‐tethered dienynes. These reactions afford bicyclo[4.1.0]heptene derivatives displaying three contiguous stereogenic centers
Iron-Catalyzed Reductive Cyclization of 1,6-Enynes
作者:Aijun Lin、Zhi-Wei Zhang、Jiong Yang
DOI:10.1021/ol403257x
日期:2014.1.17
A precatalyst of FeCl2 and iminopyridine was activated in situ by a combination of diethylzinc and magnesiumbromideetherate; it catalyzed the reductive cyclization of 1,6-enynes to give pyrrolidine and tetrahydrofuran derivatives from N- and O-tethered 1,6-enynes. The scope of the transformation was explored.
Pd(<scp>ii</scp>)-catalyzed formal [4+1] cycloaddition reactions of diazoacetates and aryl propargyl alcohols to form 2,5-dihydrofurans
作者:Taoda Shi、Xin Guo、Shenghan Teng、Wenhao Hu
DOI:10.1039/c5cc05000f
日期:——
Pd(ii)-catalyzed auto-tandem formal [4+1] cycloaddition of diazoacetates and aryl propargyl alcohols affords 2,5-dihydrofurans as the dominant product over traditional ones.