Enantioselective Synthesis of Alcohols and Amines: The Yang Synthesis of Colchicine
Guosheng Liu of the Shanghai Institute of Organic Chemistry devised the enantioselective Pd-catalyzed diacetoxylation of the alkene 1 to the bis-acetate 2 (Nature Catal. 2021, 4, 172. ). Bingxian Liu and Junbiao Chang of Henan Normal University and Xingwei Li of Shaanxi Normal University developed the enantioselective Rh-catalyzed amination of the gem-dimethyl group of 3, leading to the sulfonamide 4 (Angew. Chem. Int. Ed. 2021, 60, 8396. ). Jingchao Chen and Baomin Fan of Yunnan Minzu University used a Pd catalyst to reduce the γ-keto acid 5 to the γ-lactone 6 (Chem. Asian. J. 2021, 16, 1229. ). Sanzhong Luo of Tsinghua University used a diamine catalyst to mediate the combination of the β-ketoester 7 with the disulfide 8 to give the disulfide 9 (Angew. Chem. Int. Ed. 2021, 60, 10971. ).
Guosheng Liu also developed the enantioselective Pd-catalyzd oxidative carbonylation of the terminal alkene 10 leading to the acylated β-hydroxy ester 11 (Angew. Chem. Int. Ed. 2021, 60, 14881. ). Pere Clapés of ICIQ optimized the enzymatic homologation of the aldehyde 12 with 13 to the β-hydroxy acid 14 (ACS Catal. 2021, 11, 4660. ). Ji-Bao Xia of the Lanzhou Institute of Chemical Physics achieved high regioselectivity and diastereoselectivity in the coupling of the enantiomerically-pure aldehyde 15 with the alkyne 16 to give the allylic alcohol 17 (J. Am. Chem. Soc. 2021, 143, 7306. ). Anita E. Mattson of Worcester Polytechnic Institute assembled the tertiary ether 20 by adding the alkyne 19 to the ester 18 (ACS Catal. 2021, 11, 6325. ).
Bian Wu of the Institute of Microbiology of the Chinese Academy of Sciences optimized a lyase for the amination of 21 to give the β-amino acid 22 (Nature Catal. 2021, 4, 364. ). Abing Duan of Hunan University and Shu-Yu Zhang of Shanghai Jiao Tong University coupled the unsaturated amide 23 with the azodicarboxylate 24, leading to the γ-amino amide 25 (Org. Lett. 2021, 23, 25. ).
Nicolai Cramer of EPFL devised the enantioselective ortho coupling of 26 with the acrylate 27, leading to the γ-amino ester 28 (Angew. Chem. Int. Ed. 2021, 60, 655. ). Zhi Zhou and Wei Yi of Guangzhou Medical University (ACS Catal. 2021, 11, 2279. ), Yu Liu of the Changchun University of Technology and Junliang Zhang of Fudan University (Chem. Sci. 2021, 12, 8241. ) and Fen Wang and Professor Li of Shaanxi Normal University (ACS Catal. 2021, 11, 6692. ) described parallel investigations. Wusheng Guo of the Xi'an Jiaotong University assembled the γ-quaternary amine 31 by coupling aniline 30 with the carbonate 29 (J. Am. Chem. Soc. 2021, 143, 7629. ).
Many derivatives of colchicine (35) have been prepared in pursuit of improved anti-cancer activity. Yu-Rong Yang of the Kunming Institute of Botany developed a seven-step route to 35, a key transformation of which was the enantioselective preparation of the amide 34 by the Ir-catalyzed coupling of the racemic allylic alcohol 32 with acetamide 33 (Org. Lett. 2021, 23, 2731. ).