REGIOCONTROLLED AND STEREOCONTROLLED FUNCTIONALIZATION OF ACYCLIC MOLYBDENUM ETA-3-ALLYL COMPLEXES

被引:53
作者
VONG, WJ
PENG, SM
LIN, SH
LIN, WJ
LIU, RS
机构
[1] NATL TSING HUA UNIV,DEPT CHEM,HSINCHU 30043,TAIWAN
[2] NATL TAIWAN UNIV,DEPT CHEM,TAIPEI 10764,TAIWAN
关键词
D O I
10.1021/ja00002a027
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Chemical transformation of the ester CpMo(Co)2(syn-eta-3-1-C3H4COOMe) to its eta-3-allyl alcohol, acid, acid chloride, and amide has been achieved. Treatment of CpMo(CO)2(syn-eta-3-1-C3H4CHR(OH)) (R = H (2f), CH3 (2g) with (CF3SO2)2O in ether at -78-degrees-C stereoselectively generates, the air-stable s-trans-eta-4-diene cations, which have been characterized by appropriate physical methods. The ionization process proceeds via an intramolecular S(N)2 mode. The s-trans-eta-4-cis-pentadiene cation reacts with water, alcohol, thiol, and amine to give eta-3-allyl derivatives, which retain the same configuration as that of 2g. The enolate CpMo(CO)2(syn-eta-3-1-C3H4COCH2Li) condenses with aldehyde at -78-degrees-C to yield the aldol products CpMo(CO)2(syn-eta-3-1-C3H4COCH2CHR(OH)) (R = Ph (6a), CH3 (6b) (CH3)2CH (6c)) with good diastereoselectivity. The major diastereomer has been isolated and characterized by X-ray diffraction. Further reduction of this diastereomer with NaBH4 produces the corresponding 1,3-diol as a single diastereomer. Utilization of 2g and 6e in synthesis of acyclic 1,3-diol and 1,3,5-triol has been achieved, with excellent stereoselectivity; a mechanism is been proposed.
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页码:573 / 582
页数:10
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