在温度> 100°时,叔丁基氯化镁将R 3SiΣ型三有机硅烷(ΣCl或OCH 3)转化为氢硅烷R 3 SiH的过程同时进行两个过程:有机镁化合物的直接还原和间接的格氏试剂的热分解导致氢化镁还原。这些结果可以推广到各种空间受阻的格氏试剂的还原作用:R = C 6 H 11,C 5 H 9,iC 3 H 7。
在温度> 100°时,叔丁基氯化镁将R 3SiΣ型三有机硅烷(ΣCl或OCH 3)转化为氢硅烷R 3 SiH的过程同时进行两个过程:有机镁化合物的直接还原和间接的格氏试剂的热分解导致氢化镁还原。这些结果可以推广到各种空间受阻的格氏试剂的还原作用:R = C 6 H 11,C 5 H 9,iC 3 H 7。
Convenient route to di- and triorganosilyl ethyl ethers and the corresponding di- and triorganosilanes
作者:James M. Tour、Jens A. John、Erie B. Stephens
DOI:10.1016/0022-328x(92)83181-g
日期:1992.5
alkyl- and aryllithium reagents for the preparation of organosilyl ethyl ethers of the type R3SiOEt, R2R′SiOEt, and R2Si(OEt)2, that can be reduced to the organosilanes R3SiH, R2R′SiH, and R2SiH2, respectively. Compounds of the type RR′R′SiOEt cannot be cleanly formed. The reduction procedure involves treatment of the silyl alkoxy ethers with diisobutylaluminium hydride (DIBALH) and hydrolysis of the remaining
we show that using it as a direct HAT photocatalystenables the stepwise custom functionalization of multihydrosilanes, giving access to fully substituted silicon compounds. By exploiting this strategy, we realize preferable hydrogen abstraction of Si–H bonds in the presence of active C–H bonds, diverse functionalization of hydrosilanes (for example, alkylation, vinylation, allylation, arylation, deuteration
有机硅烷对现代人类社会至关重要,在功能材料、有机合成、药物发现和生命科学等领域有着广泛的应用。然而,它们的制备远非微不足道,杂配取代硅试剂的按需合成是一项艰巨的挑战。通过直接氢原子转移 (HAT) 光催化从氢硅烷中产生甲硅烷基代表了氢硅烷活化的原子、步骤、氧化还原和催化剂最经济的途径。在这里,鉴于中性伊红 Y 的绿色特性(例如其丰富、低成本、无金属、吸收可见光和出色的选择性),我们表明将其用作直接 HAT 光催化剂可以实现逐步定制功能化多氢硅烷,获得完全取代的硅化合物。通过利用这一策略,我们实现了在活性 C-H 键存在下优选的 Si-H 键夺氢、氢硅烷的多样化功能化(例如,烷基化、乙烯基化、烯丙基化、芳基化、氘化、氧化和卤化),并且显着二氢硅烷和三氢硅烷的选择性单官能化。
Malignant Peripheral Nerve Sheath Tumors with t(X;18). A Pathologic and Molecular Genetic Study
作者:Maureen J O'Sullivan、Michael Kyriakos、Xiaopei Zhu、Mark R Wick、Paul E Swanson、Louis P Dehner、Paul A Humphrey、John D Pfeifer
DOI:10.1038/modpathol.3880230
日期:2000.11
Spindle cell sarcomas often present the surgical pathologist with a considerable diagnostic challenge. Malignant peripheral nerve sheath tumor, leiomyosarcoma, fibrosarcoma, and monophasic synovial sarcoma may all appear similar histologically. The application of ancillary diagnostic modalities, such as immunohistochemistry and electron microscopy, may be helpful in the differentiation of these tumors, but in cases in which these adjunctive: techniques fail to demonstrate any more definitive evidence of differentiation, tumor categorization may remain difficult. Cytogenetic and molecular genetic characterization of tumors have provided the basis for the application of molecular assays as the newest components of the diagnostic armamentarium. Because the chromosomal translocation t(X;18) has been observed repeatedly in many synovial sarcomas, it has been heralded as a diagnostic hallmark of synovial sarcoma To formally test the specificity of this translocation for the diagnosis of synovial sarcoma, RNA extracted from formalin-fixed, parrafin-embedded tissue from a variety of soft tissue and spindle cell tumors was evaluated fbr the presence of t(X;18) by reverse transcriptase-polymerase chain reaction. Although 85% of the synovial sarcomas studied demonstrated t(X;18), 75% of the malignant peripheral nerve sheath tumors in our cohort also demonstrated this translocation. We conclude that the translocation t(X;18) is not specific to synovial sarcoma and discuss the implications of the demonstration of t(X;18) in a majority of malignant peripheral nerve sheath tumors.
Petrow; Schtschukowskaja, Zhurnal Obshchei Khimii, 1955, vol. 25, p. 1128,1134;engl.Ausg.S.1083,1087
作者:Petrow、Schtschukowskaja
DOI:——
日期:——
Preparation of Organofluorosilanes Using Aqueous Hydrofluoric Acid<sup>1</sup>