Pd-Catalyzed Asymmetric Intermolecular Hydroalkoxylation of Allene: An Entry to Cyclic Acetals with Activating Group-Free and Flexible Anomeric Control
摘要:
A ligand-directed metal-catalyzed asymmetric intermolecular hydroalkoxylation of alkoxyallene is reported. Combined with ring-closing-metathesis, this reaction offers a new atom-efficient synthetic method toward various cyclic acetals with elaborate anomeric control. Synthetic utility of the reaction was demonstrated by the atom-efficient and stereodivergent access to various mono- and disaccharides.
A Stereoselective Access to Cyclic<i>cis</i>-1,2-Amino Alcohols from<i>trans</i>-1,2-Azido Alcohol Precursors
作者:Dong-gil Kim、Wook Jeong、Won Jong Lee、Soyeong Kang、Han Kyu Pak、Jaiwook Park、Young Ho Rhee
DOI:10.1002/adsc.201500267
日期:2015.5.4
2‐amino alcohols from trans‐1,2‐azido alcoholprecursors was developed. The key step is highlighted by the stereoselective reduction of the cyclic α‐alkoxy imines, which could be prepared from the corresponding azides by ruthenium catalysis under photolytic conditions. Remarkably, this unprecedented reaction pathway offers a stereodivergent access to structurally diverse cyclic 1,2‐amino alcohols.
Ru-Catalyzed Chemoselective Olefin Migration Reaction of Cyclic Allylic Acetals to Enol Acetals
作者:Kyeongdeok Seo、Ye ji Kim、Young Ho Rhee
DOI:10.1021/acs.orglett.7b03900
日期:2018.2.16
A Ru-catalyzed olefin migration reaction of chiral cyclic allylic acetal is reported. The reaction generates cyclic enol acetal in a highly chemoselective manner. A variety of O,O- and N,O-acetals participated in the reaction with conservation of the stereochemical integrity of the acetal moiety. The utility of the reaction was demonstrated by the short and protective group-free syntheses of (L)-deoxyribonucleoside