銠金屬催化不對稱轉換

Abstract

中文摘要 本篇論文係利用銠金屬錯合物及掌性雙環[2.2.1]雙烯配體形成之催化劑催化不對稱1,4-加成反應暨催化環化反應，總共分為三個主題。 一、銠金屬催化苯並環丁醇選擇性開環、芳基化及成碳環聯繼反應：合成掌性及多樣化多官能團[6.6.5]稠環及[6.5.5]螺環化合物 本篇主題描述利用銠金屬及掌性雙環[2.2.1]雙烯配體或軸掌性雙磷配體所形成之催化劑催化具有不同官能基的苯並環丁醇37進行選擇性開環反應，並對馬來亞醯胺59進行芳基化反應，進一步進行分子內環化反應則可以得到多環化合物。若使用掌性雙環[2.2.1]雙烯配體形成之催化劑催化反應，使用甲苯為反應溶劑，反應溫度為60 °C，可以得到掌性[6.6.5]稠環化合物60，總共23個例子，產率為21–81%，鏡像超越值為95– >99.5%；使用軸掌性雙磷配體作為配體，在相同的反應條件下則可以得到[6.5.5]螺環化合物63，總共10個例子，產率為24–71%，鏡像超越值為26–72%。

關鍵字: 銠金屬(I)催化、選擇性開環、掌性雙環[2.2.1]雙烯配體、軸掌性雙磷配體、掌性及多樣化多官能團[6.6.5]稠環及[6.5.5]螺環化合物

二、銠金屬催化苯並環丁醇選擇性開環、芳基化及成環聯繼反應：對雜原子連接丙炔官能基之環己二烯酮進行去對稱骨牌環化反應 本篇主題描述利用銠金屬及掌性雙環[2.2.1]雙烯配體所形成之催化劑催化對具有不同官能基的苯並環丁醇37進行選擇性開環反應，對雜原子連接丙炔官能基進行芳基化，再進行分子內1,4-加成反應或分子內1,2-加成反應實現去對稱化的過程，總共11個例子，產物產率最高為95%，鏡像超越值最高為99.5%。該反應特色是可藉由不同官能基立體阻礙的程度，造成其具有不同的化學反應性，最終選擇進行分子內不對稱1,4-加成反應形成化合物113，或1,2-加成反應形成化合物114，建立單一立體中心。

關鍵字: 銠金屬(I)催化、掌性雙環[2.2.1]雙烯配體、選擇性開環、去對稱骨牌環化反應

三、 銠金屬催化芳基硼酸行不對稱1,4-加成反應：合成掌性β-雙芳基取代磷酯化合物 本篇主題描述利用銠金屬及雙環[2.2.1]雙烯配體所形成之催化劑催化芳基硼酸與β-芳基取代不飽和磷酯化合物進行1,4-加成反應，得到一系列具有β立體中心的掌性磷酯化合物，總共20個例子，產率最高達到87%，鏡像超越值最高可達到99%。關鍵字: 銠金屬(I)催化、1,4-加成反應、性β-雙芳基取代磷酯化合物

Abstract This thesis herein delineates the employment of Rh(I)-catalysts, generated from chiral bicyclo[2.2.1]heptadiene ligands, in the enantioselective reactions of three distinct cate-gories of substrates. 1. Enantioselective and Divergent Synthesis of Functionalized Tetralinols and Spi-roindanols. In this study, the cascade reactions encompassing Rh(I)-catalyzed site selective C-C bond cleavage of benzocyclobutenols, enantioselective arylation with N-substituted ma-leimides and subsequent intramolecular carbocyclization are investigated. The reaction, carried in the presence of hydroxo rhodium chiral diene complex, provides tetralinols bearing three appealingly consecutive stereogenic centers in a considerably diastereo- and enantio-selective fashion. On the contrary, however, the same reactions, conducted with rhodium catalysts generated from axial chiral bisphosphine ligands, distinctively furnish chiral spiroindanols, though with moderate enantioselectivities.Key word: rhodium(I)-catalyzed、Enantioselective and Divergent Synthesis、benzocyclobutenol、maleimide、hydroxo rhodium chiral diene complex、axial chiral bisphosphine

2. Rhodium-Catalyzed Desymmetrization of Propargyl Alcohol-Tethered Cyclo-hexadienones In this study, the Rh-catalyzed site selective ring opening of benzocyclobutenols 37, re-gioselectively forming aryl-rhodium intermediates, triggers a tandem reaction of addi-tion reactions to alkynes, yielding alkenyl-rhodium species for theensuing alkenylation of the tethered cyclohexadienones. In a site-selective and desymmetrized manner, the reaction cascade ultimately furnishes chiral adducts 113 or 114 having a cyclohexadi-enone moiety with quaternary stereogenic center.Key word: rhodium(I)-catalyzed、Desymmetrization、benzocyclobutenol、Cyclohexadienone

3. Rhodium-Catalyzed Enantioselective 1,4-addition of Arylboronic Acids to β-Aryl Substituted Unsaturated Phosphonates This study depicts the use of a chiral Rh-diene catalyst in the enantioselective 1,4-addition reaction of assorted arylboronic acids with β-aryl substituted unsaturated phosphonates. The asymmetric transformation, catalyzed by 3.0 mol% of Rh/L5 gener-ated in situ, provides chiral adducts in 27–87% and with up to 99% ee under optimal conditions. Interestingly, the alkene geometry of substrates controls the stereochemical outcomes of the adducts.Key word: Rhodium(I)-Catalyzed、Enantioselective 1,4-addition、β-Aryl Substituted Unsaturated Phosphonates、boronic acid