Air-stable and recyclable, the CuII -(bis)oxazoline complex 1 efficiently catalyzes diastereo- and enantioselective hetero-Diels-Alder reactions between β,γ-unsaturated α-keto acid derivatives 2 and vinyl ethers for the synthesis of substituted dihydropyrans 3 [Eq. (1)]. Results of the crystalstructure analysis of 1 in combination with calculations on model compounds indicate the formation of a reactive
Cu II-(双)恶唑啉络合物1空气稳定且可回收,可有效催化β,γ-不饱和α-酮酸衍生物2和乙烯基醚之间的非对映和对映选择性杂Diels-Alder反应,用于合成取代的二氢吡喃3 [等式 (1)]。1的晶体结构分析结果与对模型化合物的计算相结合,表明通过用螯合底物取代两个H 2 O配体,形成了反应性中间体。X = OEt,N(OMe)Me;R =烷基,芳基,烷氧基,硫代苄基。
Process for producing 2-substituted thiopyrimidine-4-carboxylate
申请人:UBE INDUSTRIES, LTD.
公开号:US20030055252A1
公开(公告)日:2003-03-20
There is disclosed a process for producing a 2-substituted thiopyrimidine-4-carboxylate represented by the formula (3):
1
wherein R
2
represents a substituted or unsubstituted hydrocarbon group and R
3
represents a hydrocarbon group,
which comprises reacting an &agr;-keto ester compound represented by the formula (1):
R
1
OCH═CHCOCO
2
R
2
(1)
wherein R
1
represents a substituted or unsubstituted hydrocarbon group, and R
2
has the same meaning as defined above,
with an isothiourea compound represented by the formula (2):
2
wherein R
3
has the same meaning as defined above.
TROWITZSCH W., Z. NATURFORSCH., 1977, B32, NO 9, 1068-1071
作者:TROWITZSCH W.
DOI:——
日期:——
US6570015B2
申请人:——
公开号:US6570015B2
公开(公告)日:2003-05-27
Enantioselective Synthesis of Dihydropyrans. Catalysis of Hetero Diels−Alder Reactions by Bis(oxazoline) Copper(II) Complexes
作者:David A. Evans、Jeffrey S. Johnson、Edward J. Olhava
DOI:10.1021/ja992175i
日期:2000.3.1
C2-symmetric bis(oxazoline)−Cu(II) complexes 1 and 2 catalyze the inverse electron demand hetero Diels−Alder reaction of α,β-unsaturated carbonyl compounds (heterodiene) with electron-rich olefins (heterodienophile) in high diastereo- and enantioselectivity. α,β-Unsaturated acyl phosphonates and β,γ-unsaturated α-keto esters and amides are effective heterodienes, while enol ethers and sulfides function