摘要：
Using the catalytic system Pd(OAc)(2)/PPh3, coupling of 2,6-dibromopyridine (1) and pyrazoles (2) in a molar ratio of 1:2:base = 1:2.4:2.5 afforded the monosubstituted compounds 3 as the major products when KOtBu was used as the base. Without using the catalyst or using NaOtBu as the base the disubstituted compounds 4 were formed as the major products in yields up to 93%. Reactions of 1 and 2 in a molar ratio of 1:2:base = 1:1:1 selectively produced compounds 3 in yields up to 82% when KOtBu was used as the base. The complex from the reaction of 3 and Pd(OAc)(2) did not undergo further reaction with 1 to form 4 in the presence of a base. The base effect and inhibition of catalytic activity for Pd(OAc)(2) are discussed.
摘要：
Domino [4+2]/[2+2] cycloaddition of 2-isopropenyl-2-oxazoline 2 to 1-alkynyl Fischer carbene complexes (CO)(5)M=C(OEt)C=CPh 1 (a, M = Cr; b, W) in a 1:2 molar ratio afforded unusually stable biscarbene complexes 3a and 3b containing a novel four-, five-, and six-membered tricyclic core in 99.6% and 45.2% yields, respectively. Chain-opening beta-aminoalkenyl monocarbene complex 4b and beta-amidoalkenyl monocarbene complex 5b of tungsten were also isolated from the cycloaddition upon treatment of the reaction mixture of 1b and 2 on silica gel. Partial and full oxidation of 3a,b with pyridine N-oxide underwent efficient chemoselective stepwise demetalation to afford the corresponding monocarbene complexes 6a,b and organic diester 7, respectively, under mild conditions. The X-ray crystallographic study revealed the presence of a four-, five-, and six-membered tricyclic core in compounds 3, 6, and 7, and the methyl and oxazolindinyl groups derived from oxazoline 2 are positioned syn with respect to the azabicyclo[4.2.0]octadiene bicyclic moiety, which is oriented in the opposite direction. X-ray crystal structural data are reported for the bis- and monocarbene complexes 3a, 5b, and 6b as well as for diester 7.
作者机构：
[肖文精; Thay A. Ung; Richard L Pederson] College of Chemistry,Central China Normal University,Wuhan,Hubei,P. R. China;[肖文精; Thay A. Ung; Richard L Pederson] Materia,12 N. Altadena Dr.,Pasadena,CA 91107,USA
会议名称：
第六届全国磷化学化工学术讨论会
会议时间：
2003-09
会议地点：
中国湖北武汉
会议论文集名称：
第六届全国磷化学化工学术讨论会论文摘要集
摘要：
<正> Chiral allylic amines have been well known as important synthetic precursors to a number of compounds, such as functionalized piperidinones1,2, haptens3, and isoxazoline derivativesn4.In the course of the synthesis of novel HIV-protease inhibitors, we have developed an efficient approach to the
作者机构：
[Lu, SM] Cent China Normal Univ, Dept Chem, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Inst Organ Synth, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Lu, SM] C;Cent China Normal Univ, Dept Chem, Wuhan 430079, Hubei, Peoples R China.
摘要：
N-Alkylation of phosphonium salt 1 with 1H-1,2,4-triazole gave gamma -triazolylpropyltriphenylphosphonium bromide 2, which reacted with aromatic aldehydes 3 under the phase transfer conditions to afford beta -triazolylalkenes 4.
期刊：
PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS,2000年167(1):195-203 ISSN：1042-6507
通讯作者：
Lu, SM
作者机构：
[Lu, SM] Cent China Normal Univ, Dept Chem, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Inst Organ Synth, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Ctr Anal & Testing, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Lu, SM] C;Cent China Normal Univ, Dept Chem, Wuhan 430079, Hubei, Peoples R China.
摘要：
Abstract Twelve l-aryl-6-(1,2,4-triazol-l-yl)-l-hexenes 4 were synthesized by N-alkylation of alkenyl bromides 3, which were obtained by the Wittig reaction of 5-hydroxypentyltriphenylphosphonium bromide 1 with various aromatic aldehydes and subsequent bromination of the resulting alkenyl alcohols 2. The preliminary bioassay results showed that new compounds 4 were active to five plant diseases.
作者机构：
Cent China Normal Univ, Dept Chem, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Organ Synth, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Ctr Anal & Testing, Wuhan 430079, Peoples R China.;[Lu, SM] Departmeent of Chemistry, Central China Normal University, Wuhan 430079, China;[Huang, WF; Xiao, WJ] Institute of Organic Systhesis, Central China Normal University, Wuhan 430079, China
通讯机构：
[Lu, S.M.] D;Departmeent of Chemistry, Central China Normal University, China
摘要：
A series of new ω-azolylalkenes 3 were synthesized by N-alkylation of ω-bromoalkenes 2 which were obtained by Witting reaction of ω-hydroxyalkylphosphonium bromide with aromatic aldehydes and subsequent bromination. The structures of products were confirmed by 1HNMR, IR, MS and elemental analysis. The preliminary bioassay indicated that some of them had high fungicidal activities.
作者机构：
CENT CHINA NORMAL UNIV,INST ORGAN SYNTH,WUHAN 430070,HUBEI,PEOPLES R CHINA;CENT CHINA NORMAL UNIV,CTR ANAL & TESTING,WUHAN 430070,HUBEI,PEOPLES R CHINA
摘要：
omega-Azolylalkenes 3, 4, and 5 were synthesized by N-alkylation or C-alkylation of omega-bromoalkenes 2, which were obtained either by phase transfer Wittig reactions of omega-bromoalkylphosphonium salts 1 with aldehydes or by Wittig reactions of omega-hydroxyalkylphosphonium salts 6 with aldehydes and subsequent bromination. omega-Azolylalkenes 3 were also directly prepared by the Wittig reaction of omega-azolylalkyltriphenylphosphonium salts 8 with aromatic aldehydes. The stereochemistry of these Wittig reactions tvas studied. (C) 1997 John Wiley & Sons, Inc.
