-Substituted -amino acids, -substituted -amino acid derivatives, and -substituted -amino acid analogs and (bio)isosteres and their use as chemotherapeutic agents are disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres are selective LAT1/4F2hc substrates, capable of passing through the blood-brain barrier, and exhibit rapid uptake and retention in tumors expressing the LAT1/4F2hc transporter. Methods of synthesizing the -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres and methods of using the compounds for treating tumors are also disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres exhibit an improved selectivity toward tumor cells expressing the LAT1/4F2hc transporter and accumulate in cancerous cells when administered to a subject in vivo. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres exhibit an increased efficacy on a variety of tumor types.

-Substituted -amino acids, -substituted -amino acid derivatives, and -substituted -amino acid analogs and (bio)isosteres and their use as chemotherapeutic agents are disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres are selective LAT1/4F2hc substrates and exhibit rapid uptake and retention in tumors expressing the LAT1/4F2hc transporter. Methods of synthesizing the -substituted -amino acid derivatives and -substituted -amino acid analogs and methods of using the compounds for treating cancer are also disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs exhibit selective uptake in tumor cells expressing the LAT1/4F2hc transporter and accumulate in cancerous cells when administered to a subject in vivo. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres exhibit cytotoxicity toward several tumor types.

-Substituted -amino acids, -substituted -amino acid derivatives, and -substituted -amino acid analogs and (bio)isosteres and their use as chemotherapeutic agents are disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres are selective LAT1/4F2hc substrates and exhibit rapid uptake and retention in tumors expressing the LAT1/4F2hc transporter. Methods of synthesizing the -substituted -amino acid derivatives and -substituted -amino acid analogs and methods of using the compounds for treating cancer are also disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs exhibit selective uptake in tumor cells expressing the LAT1/4F2hc transporter and accumulate in cancerous cells when administered to a subject in vivo. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres exhibit cytotoxicity toward several tumor types.

-Substituted -amino acids, -substituted -amino acid derivatives, and -substituted -amino acid analogs and (bio)isosteres and their use as chemotherapeutic agents are disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres are selective LAT1/4F2hc substrates, capable of passing through the blood-brain barrier, and exhibit rapid uptake and retention in tumors expressing the LAT1/4F2hc transporter. Methods of synthesizing the -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres and methods of using the compounds for treating tumors are also disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres exhibit an improved selectivity toward tumor cells expressing the LAT1/4F2hc transporter and accumulate in cancerous cells when administered to a subject in vivo. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres exhibit an increased efficacy on a variety of tumor types.

-Substituted -amino acids, -substituted -amino acid derivatives, and -substituted -amino acid analogs and (bio)isosteres and their use as chemotherapeutic agents are disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres are selective LAT1/4F2hc substrates, capable of passing through the blood-brain barrier, and exhibit rapid uptake and retention in tumors expressing the LAT1/4F2hc transporter. Methods of synthesizing the -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres and methods of using the compounds for treating tumors are also disclosed. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres exhibit an improved selectivity toward tumor cells expressing the LAT1/4F2hc transporter and accumulate in cancerous cells when administered to a subject in vivo. The -substituted -amino acid derivatives and -substituted -amino acid analogs and (bio)isosteres exhibit an increased efficacy on a variety of tumor types.

A phosphinate or a composition of phosphinates obtainable or obtained by reacting at least a phosphinic acid of formula (I) with an oxirane of formula (II):

##STR00001## wherein R1 and R2 are the same or different and independently represent H or a hydrocarbyl radical, with the exception that R1 and R2 may not each be H at the same time and with the hydrocarbyl radical selected from C.sub.1-C.sub.10 alkyl groups, and wherein R3 is an alkylenyl group which is optionally substituted with a heteroatom selected from O, N and S.

The phosphinate or phosphinate composition thus obtained can be used as reactive or additive flame retardant, to manufacture flame-retardant polymers or flame-retardant polymer compositions.

The present invention provides reactive multi-functional dialkyl phosphinate compound(s), serving as highly efficient reactive flame retardants in flexible polyurethane foams. The invention further provides fire-retarded polyurethane compositions comprising said multi-functional dialkyl phosphinate compound and applications containing the same.