Entropy-Controlled Catalytic Asymmetric 1,4-Type Friedel-Crafts Reaction of Phenols Using Conformationally Flexible Guanidine/Bisthiourea Organocatalyst
                                
                                    
                                        作者:Yoshihiro Sohtome、Bongki Shin、Natsuko Horitsugi、Rika Takagi、Keiichi Noguchi、Kazuo Nagasawa                                    
                                    
                                        DOI:10.1002/anie.201003172
                                    
                                    
                                        日期:——
                                    
                                    Soft and weak cooperation: Conformationally flexible organic compounds were found to promote the title transformation. These “soft” organocatalysts, which are able to control processes through the differential activation entropies (ΔΔS≠S−R) of the reactive intermediates, lead to high stereoselectivities without the requirement of fine‐tuning the reaction temperatures (see scheme).
                                    软弱合作:构象灵活的有机化合物可促进标题转换。这些“软”有机催化剂,其能够控制通过差动活化熵(ΔΔ过程小号≠小号- - [R )的活性中间体导致高的立体选择性,而不微调反应温度的要求(见方案)。