TY - JOUR
T1 - Development of new synthetic method and function of ynolate anions
AU - Shindo, M.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2000
Y1 - 2000
N2 - Ynolates are carbanions having a triple bond in place of the double bond in enolate anions. Ynolates are ketene anion equivalents, thus ynolates introduce a ketene unit into substrates and the resulting products possess high reactivity. This allows ynolates to undergo unique reaction sequences. For the past 20 years, several methods for the generation of ynolates and their reactions have been developed. Recently, we have developed a novel efficient method for their generation via cleavage of ester dianions. Starting from this success, we have found new reactions of ynolate anions. Ynolate anions react with carbonyl compounds to give β-lactone enolates, which are converted into olefins with high E-selectivity. It is noteworthy that high E-selectivity was achieved in the synthesis of tetrasubstituted olefins. Utilizing the strong nucleophilicity of the β-lactone enolates, we have succeeded in the first tandem [2+2] cycloaddition-Dieckmann condensation to lead synthetically useful 2,3-disubstituted-2-cycloalkenones in good yields. Ynolate anions were found to react with N-sulfonyl aldimines to give β-lactams. N-2-methoxyphenyl aldimines efficiently activate their cycloaddition of lithium ynolates via chelation to give β-lactams and α,β-unsaturated amides. We have demonstrated the high functionality of ynolate anions. Ynolate chemistry has begun and much remains to be discovered.
AB - Ynolates are carbanions having a triple bond in place of the double bond in enolate anions. Ynolates are ketene anion equivalents, thus ynolates introduce a ketene unit into substrates and the resulting products possess high reactivity. This allows ynolates to undergo unique reaction sequences. For the past 20 years, several methods for the generation of ynolates and their reactions have been developed. Recently, we have developed a novel efficient method for their generation via cleavage of ester dianions. Starting from this success, we have found new reactions of ynolate anions. Ynolate anions react with carbonyl compounds to give β-lactone enolates, which are converted into olefins with high E-selectivity. It is noteworthy that high E-selectivity was achieved in the synthesis of tetrasubstituted olefins. Utilizing the strong nucleophilicity of the β-lactone enolates, we have succeeded in the first tandem [2+2] cycloaddition-Dieckmann condensation to lead synthetically useful 2,3-disubstituted-2-cycloalkenones in good yields. Ynolate anions were found to react with N-sulfonyl aldimines to give β-lactams. N-2-methoxyphenyl aldimines efficiently activate their cycloaddition of lithium ynolates via chelation to give β-lactams and α,β-unsaturated amides. We have demonstrated the high functionality of ynolate anions. Ynolate chemistry has begun and much remains to be discovered.
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U2 - 10.1248/yakushi1947.120.12_1233
DO - 10.1248/yakushi1947.120.12_1233
M3 - Review article
C2 - 11193376
AN - SCOPUS:0034533038
VL - 120
SP - 1233
EP - 1246
JO - Yakugaku Zasshi
JF - Yakugaku Zasshi
SN - 0031-6903
IS - 12
ER -