Solid phase synthesis of a diketopiperazine catalyst containing the unnatural amino acid (S)-norarginine
作者:Jennifer Kowalski、Mark A. Lipton
DOI:10.1016/0040-4039(96)01239-7
日期:1996.8
A cyclic dipeptide containing the unnatural amino acid (S)-norarginine, recently shown to display useful catalytic activity, has been synthesized in good yield and high chemical purity using a solid phase protocol. All reactions in the sequence, including a Hofmann rearrangement and cyclization to diketopiperazine, were performed on the Merrifield polystyrene resin and proceed in high yield. In addition
A new reagent for solid and solution phase synthesis of protected guanidines from amines
作者:Yaw Fui Yong、Jennifer A. Kowalski、Jason C. Thoen、Mark A. Lipton
DOI:10.1016/s0040-4039(98)80017-8
日期:1999.1
A newreagent -- 4-nitro-1-H-pyrazole-1-[N, N′-bis(tert-butoxycarbonyl)]car☐amidine -- has been developed to effect the rapid and efficient synthesis of bis(carbamate)-protected guanidines from primary and secondary amines. The reagent is a more electrophilic, and consequently more reactive, derivative of the literature reagent 1-H-pyrazole-1-[N, N′-bis(tert-butoxycarbonyl)]car☐amidine. The increased