Organic Chemistry Portal
Organic Chemistry Highlights

Monday, July 8, 2019
Douglass F. Taber
University of Delaware

Enantioselective Synthesis of Alcohols and Amines: The Zhang/Liu Synthesis of (-)-Cephalotaxine

Chong-Dao Lu of Yunnan University rearranged 1 to 2 (Angew. Chem. Int. Ed. 2018, 57, 15583. DOI: 10.1002/anie.201809551). Karl Anker Jørgensen of Aarhus University coupled 4 with 3 to give 5 in high ee (J. Am. Chem. Soc. 2018, 140, 12687. DOI: 10.1021/jacs.8b07394).

Benjamin List of the Max-Planck-Institut für Kohlenforschung used a sterically confined acid to mediate the addition of 7 to 6, leading to 8 (Science 2018, 362, 216. DOI: 10.1126/science.aau0817). Liang Yin of the Shanghai Institute of Organic Chemistry assembled the lactone 11 by adding 10 to enantiomerically-pure 9 (J. Am. Chem. Soc. 2018, 140, 12270. DOI: 10.1021/jacs.8b07929). Ming Chen of Auburn University prepared the homopropargylic alcohol 14 by adding 13 to 12 (Org. Lett. 2018, 20, 3810. DOI: 10.1021/acs.orglett.8b01399) and 17 by adding 16 to 15 (Adv. Synth. Catal. 2018, 360, 4634. DOI: 10.1002/adsc.201801080). Both transformations were catalyzed by the same enantiomerically-pure phosphoric acid.

Frank Glorius of the Westfälische Wilhelms-Universität Münster achieved high enantioselectivity in the hydrogenation of the 2-oxazolone 18 to the oxazolidinone 19 (Chem. Sci. 2018, 9, 6260. DOI: 10.1039/C8SC01869C). Steven J. Malcolmson of Duke University used a Pd catalyst to add 21 regioselectively and enantioselectively to 20, leading to 22 (ACS Catal. 2018, 8, 8468. DOI: 10.1021/acscatal.8b01914). X. Peter Zhang of Boston College cyclized 23 to 24 in high ee (Angew. Chem. Int. Ed. 2018, 57, 16837. DOI: 10.1002/anie.201808923). Noah Z. Burns of Stanford University also achieved high ee in the oxidative conversion of the allylic alcohol 25 to the bromo azide 26 (J. Am. Chem. Soc. 2018, 140, 15646. DOI: 10.1021/jacs.8b10799).

Keiji Maruoka of Kyoto University used a phase transfer catalyst to mediate the alkylation of 27 with 28, leading to 29 (Chem. Asian. J. 2018, 13, 1780. DOI: 10.1002/asia.201800652). Yasushi Yoshida of Chiba University used a different phase transfer catalyst to mediate the addition of 30 to 31 to give 32 (Adv. Synth. Catal. 2018, 360, 4142. DOI: 10.1002/adsc.201800791).

(-)-Cephalotaxine (35), isolated from the Korean plum yew Cephalotaxus harringtonii, is the parent of a family of bioactive alkaloids. En route to 35, Zhi-Wei Zhang and Souxin Liu of the Hebei University of Science and Technology rearranged 33 to 34 in high ee (Org. Lett. 2018, 20, 1050. DOI: 10.1021/acs.orglett.7b04008).

D. F. Taber, Org. Chem. Highlights 2019, July 8.