378238-39-2Relevant academic research and scientific papers
A general method for the asymmetric synthesis of both enantiomers of 1-substituted 1,2,3,4-tetrahydro-β-carbolines employing pyroglutamic acid derivatives as chiral auxiliaries
Itoh, Takashi,Miyazaki, Michiko,Ikeda, Sachiko,Nagata, Kazuhiro,Yokoya, Masashi,Matsuya, Yuji,Enomoto, Yasuko,Ohsawa, Akio
, p. 3527 - 3536 (2007/10/03)
9-(S)-Pyroglutaminyl-β-carbolines were allowed to react with a nucleophile (allyltributyltin or a silyl enol ether) in the presence of 2,2,2-trichloroethyl chloroformate to give 1,2-addition products in good yields and high diastereoselectivity. The chiral auxiliary at N-9 was readily removed by a mild hydrolysis. The same chiral source afforded both enantiomers by simply altering a protecting group of the amide nitrogen. That is, (S)-pyroglutaminyl groups which had an N-alkyl group afforded the (S) isomer, whereas the ones having an N-acyl group produced the (R) isomer of the addition products.
A new entry to asymmetric synthesis of 1-substituted 1,2,3,4-tetrahydro-β-carbolines employing a pyroglutamic acid derivative as a chiral auxiliary
Itoh, Takashi,Nagata, Kazuhiro,Yokoya, Masashi,Miyazaki, Michiko,Ikeda, Sachiko,Matsuya, Yuji,Enomoto, Yasuko,Ohsawa, Akio
, p. 1005 - 1007 (2007/10/03)
β-Carboline which was protected at N-9 by an acyl group derived from L-pyroglutamic acid reacted with allyltributyltin or silyl enol ethers in the presence of an alkyl chloroformate in a highly diastereoselective manner to give 1-substituted 1,2-dihydro-β
Preparation of both enantiomers of 1-allyl-1,2,3,4-tetrahydro-β-carboline using allyltin reagents and a chiral auxiliary derived from L-proline
Itoh, Takashi,Matsuya, Y?ji,Enomoto, Yasuko,Ohsawa, Akio
, p. 7277 - 7289 (2007/10/03)
β-Carboline, which had an acyl group derived from L-proline at the 9-position, reacted with allyltributyltin and 2,2,2-trichloroethyl chloroformate to afford an 1-allyl-1,2-dihydro-β-carboline derivative in a diastereoselective manner. The chiral acyl group at N-9 was readily eliminated by aqueous alkali to give a corresponding carboxylic acid. The formed 1-allyl-1,2-dihydro-β-carboline was transformed via two reduction steps to 1-allyl-1,2,3,4-tetrahydro-β-carboline in high ee. When the allylation was carried out using tetraallyltin instead of allyltributyltin, the stereoselectivity was reversed, and the antipode of the allyl adduct was obtained in high yield and ee in the presence of tin(IV) tetraiodide. Thus, it was found that both enantiomers of 1-allyl-β-carboline were obtained in good enantioselectivities by the use of the same chiral auxiliary.
