Enantioselective Synthesis of (Thiolan-2-yl)diphenylmethanol and Its Application in Asymmetric, Catalytic Sulfur Ylide-Mediated Epoxidation
作者:Hsin-Yi Wu、Chih-Wei Chang、Rong-Jie Chein
DOI:10.1021/jo400648f
日期:2013.6.7
This work describes an expeditious and efficient preparation of enantiopure (thiolan-2-yl)diphenylmethanol (2) featuring a double nucleophilic substitution and Shi epoxidation as key steps. One of the applications of its benzyl ether derivative to asymmetric sulfur ylide-mediated epoxidation with up to 92% ee (14 examples) was also demonstrated herein.
A new generation of 2,5-dimethylthiolanes with a locked conformation was developed to promote the asymmetric addition of chiralsulfoniumylides to aldehydes. The novel chiral sulfur derivative 4 succeeded the synthesis of trans-stilbene oxide derivatives with enantiomeric ratios ranging from 95:5 to 98:2. This user-friendly organocatalytic process proved to be efficient with 20−10% of sulfide 4 in
A new chrial organosulfide was synthesized through an unexpected Wagner–Meerwein rearrangement. This organosulfide could catalyze the epoxidation reaction of various aromatic aldehydes smoothly with benzyl bromide to give trans-diaryl epoxides in satisfactory yields (60–84%) with excellent diastereoselectivities (trans:cis=95:5–100:0) and good to excellent enantioselectivities (86–96% ee).
New Camphor-Derived Selenonium Ylides: Enantioselective Synthesis of Chiral Epoxides
作者:Xin-Liang Li、Yi Wang、Zhi-Zhen Huang
DOI:10.1071/ch05157
日期:——
selenonium salts 3 as the precursors of two new chiral selenonium ylides 4 can be synthesized stereoselectively from natural d-camphor in good yields. It is found that the reaction of the selenonium salt 3b, an aldehyde, and potassium tert-butoxide can take place smoothly in ‘one-pot’ via the formation of selenonium ylide 4b, to give chiral trans-diaryl epoxides 5 in good yields with good diastereoselectivities
A Novel and Highly Efficient Asymmetric Synthesis of Epoxides via Chiral Telluronium Ylides
作者:Zhi-Zhen Huang、Wen-Hua Ou
DOI:10.1055/s-2005-872169
日期:——
The one-pot reaction of telluronium salt 8, aldehyde, and potassium tert-butoxide proceeded smoothly via chiral benzyl telluroniumylide, producing trans-(2S,3S)-diaryl epoxides with good yields as well as excellent diastereoselectivities and enantioselectivities (up to 99% ee).