Enantioselective synthesis of non-proteinogenic amino acids via metallated bis-lactim ethers of 2,5-diketopiperazines
作者:Ulrich Schöllkopf
DOI:10.1016/s0040-4020(01)91926-x
日期:1983.1
excess = asymmetric induction) of the adduct exceeds 95%. On hydrolysis the adducts are cleaved liberating the chiral auxiliary (used to build up the bis-lactim ether 1) and the target molecules, the opticallyactive amino acid methyl esters of type 8,19,25 or 36. The two amino acid esters are separable either by fractional distillation or (eventually after further hydrolysis to amino acids) by chromatography
Total Synthesis and Structure Elucidation of JBIR-39: A Linear Hexapeptide Possessing Piperazic Acid and γ-Hydroxypiperazic Acid Residues
作者:Masahito Yoshida、Naoki Sekioka、Miho Izumikawa、Ikuko Kozone、Motoki Takagi、Kazuo Shin-ya、Takayuki Doi
DOI:10.1002/chem.201406020
日期:2015.2.9
The totalsynthesis and stereochemical structural elucidation of JBIR‐39, containing four nonproteinogenic piperazic acid (Piz) residues, is reported. The synthesis includes Sc(OTf)3‐catalyzed acylation of a Piz(γ‐OTBS) derivative with piperazic acid chloride, providing the desired Piz‐Piz(γ‐OTBS) dipeptide in high yield without epimerization. After assembling two additional Piz moieties and (S)‐isoleucic
N,N-Dialkyl-β-amino alcohols were enantiospecifically and regioselectively rearranged by using N,N-diethylaminosulfur trifluoride (DAST) to give optically active β-fluoroamines in excellent yields and enantiomeric excesses. This rearrangement was applied to the enantioselectivesynthesis of LY503430, a potential therapeutic agent for Parkinson’s disease.
Total Synthesis of Tambromycin Enabled by Indole C–H Functionalization
作者:Galen P. Miley、Jennifer C. Rote、Richard B. Silverman、Neil L. Kelleher、Regan J. Thomson
DOI:10.1021/acs.orglett.8b00700
日期:2018.4.20
The totalsynthesis of tambromycin (1), a recently isolated tetrapeptide, is reported. This unusual natural product possesses a highly modified tryptophan-derived indole fragment fused to an α-methylserine-derived oxazoline ring, and a unique noncanonical amino acid residue named tambroline (11). A convergent synthesis of tambromycin was achieved by a 13-step route that leveraged recent developments
Enantioselective Electrophilic Amination of α-Cyanothioacetates with Azodicarboxylates Catalyzed by an Axially Chiral Guanidine Base
作者:Masahiro Terada、Daisuke Tsushima、Megumi Nakano
DOI:10.1002/adsc.200900594
日期:2009.11
An enantioselectiveelectrophilicamination of α-substituted cyanothioacetates with azodicarboxylate is demonstrated using an axiallychiralguanidine as a chiral Brønsted base catalyst. The corresponding product, having a quaternary stereogenic center at the α-carbon atom, is formed in excellent enantioselectivity.