β-Selective <i>C</i>-Arylation of Diisobutylaluminum Hydride Modified 1,6-Anhydroglucose: Synthesis of Canagliflozin without Recourse to Conventional Protecting Groups
作者:Julian P. Henschke、Chen-Wei Lin、Ping-Yu Wu、Wen-Shing Tsao、Jyh-Hsiung Liao、Pei-Chen Chiang
DOI:10.1021/acs.joc.5b00601
日期:2015.5.15
'The beta-selective phenylation of benzyl and boronate protected 1,6-anhydroglucose and the direct phenylation of unprotected 1,6-anhydroglucose (10), pretreated with i-Bu2AlH, i-Bu3Al, Et3Al, Me3Al, or n-octyl(3)Al, with triphenylalane or aryl(chloro)alanes is reported. The utility of the unprotected version of the method is demonstrated by the synthesis of the SGLT2 inhibitor, canagliflozin (1a), from commercially available 10 in one C-C bond-forming step. This approach circumvents the need for conventional protecting groups, and therefore no formal protection and deprotection steps are required.
报道了对苯甲基和硼酸酯保护的1,6-脱水葡萄糖的β选择性苯基化,以及对未保护的1,6-脱水葡萄糖(10),在用i-Bu2AlH、i-Bu3Al、Et3Al、Me3Al或n-octyl(3)Al预处理后,使用三苯基烷基或芳基(氯)烷基化试剂的直接苯基化。该方法的未保护版本的实用性通过从商业可得的10在一步C-C键形成步骤中合成SGLT2抑制剂卡格列净(1a)得到证明。该方法避免了传统保护基团的需要,因此不需要正式的保护和去保护步骤。